HiRes Google Satellite map -w- overlays:
https://www.google.com/maps/dir/R%C3%B8st+Municipality,+Norway/@67.6537827,12.6093592,4865m

https://fishing-app.gpsnauticalcharts.com/i-boating-fishing-web-app/fishing-marine-charts-navigation.html#10.33/67.4802/12.0486

https://kart.opplevrost.no/map/?Walk=53

https://nordlandsatlas.maps.arcgis.com/apps/webappviewer/index.html?id=fab455cbf6e8441894efd4ccc99a0b8f

A detailed map showing trade lanes and beacons: +++
https://map.openseamap.org/
Shipping map key: https://openseamap.org/index.php?id=schiffstracking&L=0
Weather map key: https://openseamap.org/index.php?id=wetter&L=1
Another really great nav map with photo background & other options:
https://www.barentswatch.no/bolgevarsel/point/12.073554081583126_67.50643332862725

LIVE weathermap:
https://www.meteoblue.com/en/weather/maps/lofoten_norway_3147088#coords=10.37/67.7272/12.7595&map=cape~hourly~auto~sfc~windAnimationOverlay

Rost area weather map:
https://www.yr.no/en/map/weather/1-272622/Norway/Nordland/R%C3%B8st/R%C3%B8st

Sun position Analemma
https://www.sunearthtools.com/dp/tools/pos_sun.php

Topographic Map:
https://en-ca.topographic-map.com/map-drv8tf/Lofoten/?center=67.66278%2C12.6384&zoom=11
Incredible bathometric map of the world - with some insight into Lofoten Island seafloor:
https://seabed2030.org/
Also another showing seafloor in the region:
https://download.gebco.net/

https://richiecarmichael.github.io/landsat/index.html
https://www.barentswatch.no/bolgevarsel/currentwavespoints/Moskstraumen
https://www.farleia-forlag.no/moskstraumen/index_mosk_eng.html

A discussion about the maelstrom:
https://steamproxy.com/app/1266540/discussions/0/4694532668678792888/

Researchgate overview of the maelsrom: +++
https://www.researchgate.net/figure/The-many-views-of-Moskstraumen-a-A-photograph-of-Moskstraumen-in-the-Moskenes-Sound_fig1_354749426

https://geographical.co.uk/news/phenomena-maelstroms-and-whirlpools

Early Map of Norway (look for Maelstrom to find Lofoten Islands)
https://upload.wikimedia.org/wikipedia/commons/e/ea/Carta_Marina.jpeg

Norway lighthouses Image:






Overview map of the mid-Norwegian margin with large-scale bathymetry of the Norwegian Sea. The white dotted line marks the boundary between crystalline and sedimentary bedrock. HB, Haltenbanken; L, Lofoten Islands; NC, Norwegian Channel; SR, Skjoldryggen; TB, Trænabanken; TD, Trænadjupet; V, Vestfjorden. 642 and 644, ODP drill sites. Locations of subsequent figures are shown.
From: https://www.researchgate.net/figure/Overview-map-of-the-mid-Norwegian-margin-with-large-scale-bathymetry-of-the-Norwegian_fig1_253527596

https://www.youtube.com/watch?v=RPtYaBV5MJg&t=56s

IALA maritime buoyage systems
https://www.safe-skipper.com/an-explanation-of-the-iala-maritime-buoyage-systems-iala-a-and-iala-b/

https://en.wikipedia.org/wiki/Sector_light

https://en.wikipedia.org/wiki/PEL_sector_light

Try to upgrade your engineering (for boat repairs on the run) and upgrade eco for savings on fuel.

---------------------------------

Undocumented dashboard Zoom feature
If you (RMB), than immediately go to external view (V), it will lock the zoom view on, hit (V) again to re-enter the boat, now you simply need to point at instruments and it will auto zoom on them. Right mouse click again to restore normal view.
Try to play around with it, once you figure it out - I think you'll agree that the feature has value.
--------------------------------

Important: How to avoid grounding your boat:
The best advice at the moment is to avoid traveling through the darkest grey areas on the map.

These areas tend to have the most collision issues. Often times the threats in those areas are invisible - (not visible at or below the waterline). If you attempt to cross through such areas, you may end up stranded floating in mid air.
Take a look at a small portion of the SAS map and note the darker grey areas:


Okay, so after wanting to investigate certain areas that were in this dark grey color (places that my autopilot refused to allow me to plot a course through) I would park the boat on the edge of a grey zone, save my game and then proceed in on manual control. (recommend if you like to explore)
I was surprised to discover that I had received zero damage in my journey through - that particular grey area that was near the south west bottom of Rost.
The lesson I would draw from this is that not all dark grey areas may be as dangerous as others - or I was just lucky :)

I decided it was time to compare the various clearances of each boat for travelling over areas that are shallow. Each boat is fully kitted out (not sure if that makes a difference at this point in SAS)
Displayed waterlines are WIP - but I think they are relatively correct:


Yeah what the... might as well do RowMeo too :)

Looking at the differing depths of each hull wasn't a total surprise - although I was doubly impressed by the larger Skarven's smooth low profile compared to the others.
The Skarven's speed on top of that, is enough to make it an explorer class vessel.
The radar kit is there - It 'should' be able to give me 360 info on whats above and below the waterline. I haven't found anything in the SAS radar that resembles that mode yet. (hoping we will see such upgrades at some point, since ship radar systems look underwater as well)
(Note: Found out this ability is in the SAS radar)

Without that radar mode, it meant that I would have to rely on the fishfinder to give me some meaningful bottom depth information. The best craft with the least hull displacement that had a fishfinder was the Flippy.


Here is a picture of the Flippy as I was manually piloting it into an enclosed area within the grey zone. The depth setting on the fishfinder zoom shows 8 meters as first increment. It seems to be the most shallow setting. To get there hit Depth - , then the History Zoom.

Since my outing with the Flippy, I have found the way to skew the radar downwards via the Depth + & - button. So I will go back to the Skarven and revisit those areas.
Think of the radar beam as a spotlight that continually rotates, don't aim it all the way down or you will only see obstacles directly near your boat, giving you little time to react if moving.
Play around with it and you will find the best setting for your situation. If moving, consider your course, speed and reaction time

Instead of the sharp edges you would normally see reflected back from outcrops, you will now see a fuzzy outline around them, showing the threat below the waves.
There are options to adjust brightness to suit your preference. Using the Gain +- setting adjusts the intensity of the radar beam.

Here is an example of what you should see: (notice the stark lines of the pier and compare that to the outcrops. Part of the outcrops are above surface) I have not adjusted Gain yet.


I did a recent check on the fishfinder in the Conquest and it has the added feature of a "Forward Mode" not available on the Flippy.
More tips as I uncover them...

Since v0.8 a lot of changes have occurred that may or may not have affected the way the fishfinder performs. There does not appear to be an auto refresh, so odds are the original functions are still there.

The fact that there are now local fish habitats may have increased the speed to the catch, does not suggest the best catch is close to home.
From experience, the best catch is often in northern regions. Once seasonal aspects fully come into play, that could be in flux.

Fishfinder

Since v0.7.5 the fishfinder has been used to isolate and chase down specific types of fish.
The method required choosing your preferred catch from the main map and then plotting a course to the location.

At some point enroute to destination turn on the fishfinder.
Set the fishfinder depth so that the bottom of the ocean is visible (for best range)
Turn on the overlay.
Once you come within a certain range the yellow icon will splinter into smaller orange icons, each with their own types of fish. (on map screen) Make your way to the fish type you want to catch.

You can refresh the fishfinder a few times on the way and you may see the fish you want to target.
I usually wait until I am a the max scan range (500m) from the icon to refresh the fishfinder screen.
This method insures that I have scanned the targeted catch and not something other.

When you can look up and see the gannets flying over and diving into the water around you at 100kph is how it's designed. Hoping for a more detailed version of that experience over time.

A good vid and some images:
https://www.youtube.com/watch?v=nT6B87M22sg&ab_channel=EarthTouch

https://fishfinderguru.com/fish-finder-glossary-demystifying-technical-terms-and-jargon/

Has some vids with practical fishfinder info.
https://sportfishingbuddy.com/fish-finder-types/

Future sonar upgrades?
https://www.sonarwars.com/lowrance-hook-reveal-review/#:~:text=The%20first%20thing%20to%20understand%20is,%20you%20will

Note on radio waves:
The distance radio waves can travel through water depends on the frequency of the radio waves:
Very low frequency (VLF) and extremely low frequency (ELF)
These low frequency radio waves can travel hundreds of meters through water. They have longer wavelengths, so they interact less with water molecules than higher frequency radio waves.
Many navies use VLF radio waves to communicate with submarines.

High frequency radio waves
These radio waves can only travel short distances underwater, a few meters at most.
-------------------------------------------------------------
Passive Sonar vs active Sonar
Active sonar emits sound waves while passive sonar listens for sounds made by other objects.
Passive sonar can also be used for monitoring and studying the natural sounds of the ocean, such as marine life, seismic activity, or weather phenomena.
-------------------------------------------------------------

"Radar & Sonar Applications in Maritime Activities
From https://www.boattrader.com/

Radar Applications:
Navigation: Radar helps in plotting a vessel’s course and avoiding collisions, particularly in
unlit areas or during adverse weather conditions.
Safety: By detecting sudden weather changes and high waves, radar contributes significantly to
the safety of the vessel.
Search and Rescue: Radar is invaluable in search and rescue operations as it can detect objects
over large distances, even in challenging conditions.

Sonar Applications:
Underwater Exploration: Sonar is used to map the ocean floor, discover underwater hazards, and
locate shipwrecks.
Fishing: Commercial fishermen use sonar to locate schools of fish, significantly enhancing the
efficiency of fishing operations.
Environmental Monitoring: Sonar helps scientists in studying aquatic life and monitoring the
health of marine ecosystems.

Advantages and Disadvantages
Advantages of Radar:
Versatility: Radar can detect and track multiple targets simultaneously.
Range: High-powered radar systems have a long detection range.
Reliability: Radar is less affected by the medium through which it travels, maintaining
functionality in various weather conditions.
Disadvantages of Radar:
Clutter: Radar systems can be susceptible to clutter from rain or sea waves, which might obscure
true targets.
Interference: External sources like other radar systems can cause interference, complicating the
interpretation of radar data.

Advantages of Sonar:
Detail: Sonar provides detailed images of the underwater landscape and objects.
Depth Measurement: It accurately measures the depth of water, essential for safe navigation in
unknown waters.
Disadvantages of Sonar:
Speed: Sonar data collection and processing can be slower compared to radar.
Range Limitations: Sonar is generally limited to shorter ranges compared to radar.

Conclusion
Both radar and sonar systems offer indispensable tools for maritime navigation, safety, and exploration.
While radar provides broad coverage and rapid detection capabilities essential for surface navigation and obstacle avoidance, sonar offers unparalleled insights into the underwater world, crucial for depth determination and detailed underwater imaging. The choice between using radar or sonar depends on the specific requirements of the maritime activity. Often, vessels are equipped with both technologies to maximize safety and operational efficiency."

Above screenshot was taken at the southern most area of the map. Depending on sea state, some outcrops will periodically disappear below the waterline, becoming intermittent on the radar screen.

My experience with the SAS radar suite is that it is certainly great to have but the method of interacting with it can initially be a bit awkward due to the close proximity of buttons.
Some modes and buttons seem to work - while others are TBD.
This may simply be that the radar is still a WIP and still needs some love by SAS devs.

At any rate, it can be a great compliment to navigation, once a player becomes familiar with some of the existing available options.

In the Glossary section is listed some of the definitions for SAS radar modes and what they do in the real world. How much of that correlates with SAS is TBD.

SAS Radar Terminology list & definitions (certain 'MODE' functions may not appear in SAS)

"COG" stands for Course Over Ground, which is the resultant (straight line) direction between any two points on a vessel's track.

"SOG" stands for Speed Over Ground and represents the actual speed of progress with respect to the earth. It is measured by satellite receivers and is free from the effects of sea currents.

"EBL" stands for Electronic Bearing Line. It is used to determine the bearing from your present location to a specific target. The EBL function bisects the target and displays its bearing in the EBL readout. It appears as a dashed line. Adjust the EBL so that it bisects the target. The bearing to target appears in a data box on the display.

"VRM" stands for "Variable Range Marker". It is a circle centered on the present location of your boat, and it measures the distance and bearing from your boat to a target object. The VRM intersects with the "EBL" (Electronic Bearing Line), which is a line that begins at the present location of your boat and intersects the VRM.

Gain" Is a measure of its efficiency in transmitting and receiving signals. It is defined as the ratio of the power output to the power input and is usually expressed in decibel (dB).
The [GAIN] key adjusts the gain sensitivity of the radar receiver. It works in a manner similar to that of volume control of a broadcast receiver, which amplifies received signals.
The proper setting is such that the background noise is just visible on the screen. If your gain setting is too low, weak echoes may be missed. On the other hand, excessive gain yields too much background noise; strong targets may be missed because of the poor contrast between desired echoes and the background noise on the display.

"Rain" clutter
Echoes from rain that can be minimized or eliminated to prevent the radar from detecting desired targets. When echoes from precipitation mask solid targets, adjust the A/C RAIN to split up these unwanted echoes into a speckled pattern, making recognition of solid targets easier.

"Sea" clutter
Echoes from waves in a seaway that can be suppressed to prevent the radar from detecting desired targets. A/C SEA should be adjusted so that the clutter is broken up into small dots, and small targets become distinguishable.

"Range" Scale
The range setting determines the size of the area (in nautical miles) that will appear on your display. In addition, the range setting will also automatically adjust the range ring interval so that accurate range measurements may be made while operating on any range setting.
The range, range ring interval and pulselength appear at the top left-hand corner of the display.
Press the [RANGE (+ or -)] key to change the range scale.

Chart scale (range) may be selected with the [RANGE -] or [RANGE +] key. The [-] key shrinks the chart range (image is expanded); the [+] key expands the cart range (image is shrunk).

MODE soft key. Each pressing of the key changes the presentation mode and the presentation mode indication in the sequence of North-up, True Motion, Head-up, and Course-up.
Description of presentation modes:

North-up
In the north-up mode, targets are painted at their measured distances and in their true (compass) directions from own ship. North is maintained at the top of the screen. The heading line changes its direction according to ship’s heading.

True motion
Fixed radar targets maintain a constant position on the screen, while your own ship moves across the radar image at the correct speed and heading. A map-like image is displayed, with all moving vessels traveling in true perspective to each other and to fixed landmasses. As your ship’s position approaches the edge of the screen, the radar display is automatically reset to reveal the area ahead of your ship. You can manually reset your ship’s position at any time by pressing the RADAR DISPLY soft key followed by the SHIFT soft key.

Head-up
"H Up" refers to a radar picture where the target is head up. This is in contrast to a chart where the target is north up. A display without azimuth stabilization in which the line connecting the center with the top of the display indicates own ship’s heading. Targets are painted at their measured distances and in their directions relative to own ship’s heading. The short line on the bearing scale is the north marker.

Course-up
The radar picture is stabilized and displayed with the currently selected course at the top of the screen. As you change heading, the ship’s heading line moves. If you select a new course, the picture resets to display the new course at the top of the display.
Targets are painted at their measured distances and in their directions relative to the intended course which is maintained at the 0-degree position. The heading line moves in accordance with ship’s yawing and course changes.

Measuring the Range
You can measure the range to a radar target three ways: by the range rings, by the cursor, and by the VRM (Variable Range Marker).
2.10.1 Measuring range by range rings
Count the number of rings between the center of the display and the target. Check the range ring interval and judge the distance of the echo from the inner edge of the nearest ring.

Measuring range by VRM
1. Press the [EBL/VRM] key to display the EBL/VRM soft keys.
2. Press the VRM1 ON (dotted ring VRM) or VRM2 ON (dashed ring VRM) soft key to select the desired VRM. The selected VRM’s indication, at the bottom of the screen, is highlighted.
3. Rotate the [ENTER] knob the place the VRM on the inside edge of a radar target. Read the VRM indication to find range to the target.

Measuring bearing by EBL
1. Press the [EBL/VRM] key.
2. Press the EBL1 ON (dotted line EBL) or EBL2 ON (dashed line EBL) soft key to select the desired EBL. The selected EBL’s indication, at the bottom of the screen, is highlighted.
3. Rotate the [ENTER] knob to bisect the radar target with the EBL. Read the EBL indication to find the bearing to the target.

TX/STBY Toggles radar between standby and transmit.
Transmitting, Stand-by
1. Confirm that the network radar is plugged in.
2. Press the [DISP] key to select a radar display.
3. Press the [POWER/BRILL] key momentarily.
4. Press the RADAR STBY soft key to highlight TX on its label.
5. Press the RETURN soft key.
When the radar picture is not required, but you want keep it in a state of readiness, press the RADAR TX soft key to highlight STBY on its label.

"Transmit" refers to the process of sending out electromagnetic waves, or radio waves, from a radar system's transmitter. The transmitter generates short bursts of radio waves, called pulses, which are then radiated by the antenna in a directional beam.

"RM" stands for relative motion, which is a display mode that shows the motion of a target relative to the motion of the observing ship. In relative motion mode, the position of the observing ship is kept at the center of the image, and other targets move relative to it.
This makes it easier to judge the risk of collision, but a radar plot is needed to get information on the course and speed of other vessels. In contrast, true motion mode shows the actual motion of the target and the observing ship. In true motion mode, the position of the observing ship on the screen moves in the direction of the heading line and at the speed of the ship.

"GSR" stands for Ground Surveillance Radar, a high-tech sensor system that detects and tracks land-based targets. GSRs are used to monitor activity around critical infrastructure, such as military installations, airports, and borders

"IR" stands for interference rejection, which is a radar control that reduces interference from other radars on the radar screen.
Radar beam height: Radar beams start out close to the ground, but get higher and wider as they move away from the radar. The standard angle of elevation for a radar beam is 0.5 degrees.

From:
https://steamproxy.com/sharedfiles/filedetails/?id=3377063060

Autopilot Functions
In v0.08 Automatic Manual overide now exists when AP is on so rudder is now always functional even when AP is on.

The main functional difference between v0.7.5 auto pilot and v0.08's is how the AP waypoints are displayed. In v0.7.5 It was only a matter of placing flags, well aside from the other features, it is still pretty much the same with the flags turning into a new type of waypoint icon.
You still get to keep the flags (if you want)

The new waypoint icons are easily distinguished from flag waypoint icons - unless the AP course has been updated to include them.

The major difference involves once you place waypoint flags, you now need to transform or add them to the AP course. This can be done in 2 ways:
Hit "P" once, it should add any new AP icons to where your flags have been placed.

You can keep your flags in place. (recommended atm, since the AP plot will be deleted by hitting "P" again) but can be restored just as easily, so long as your flags are still on the map screen.

Each time you hit "P" you will cycle through all the AP modes till you get to "P" again and it will update your AP course with any new flags you have added.

The other method that does not allow saving of the flag positions involves going to the AP terminal screen, selecting NAV with "E" to transform your flags into AP icons.

v0.8 AUTO STOP
The autostop function if activated by CMD button will stop your ship at the end of the course. To see if it is engaged you need to look at the left bottom of AP screen and see a circle with "STOP" in the middle (may be hard to see unless brightness is adjusted)


v0.8 AUTO vs NAV setting
Info on the AP console's Auto setting:
(do this only if you don't mind losing your existing waypoint flags)

If you turn off the AP then set a heading, you can lock in that heading by toggling ON the Auto function at the console (disables the NAV function.)
Now when you cycle through all the AP modes you will see Auto instead of NAV.

If you decide you want to go back to setting your course with flags, place your flags on the map and next time you cycle through the AP modes the NAV function will have returned and new AP course set.

You can also turn NAV function back on at the console - but that will delete your flags.

The Auto setting works best with the rudder bias system to compensate for wind pushing the ship from a direct line to the destination from your set compass heading.

I have found that the best way to use this so that the bias can be maintained is by going to game settings and turning on "Rudder Control". This stops the rudder from autocentering so you will need to pay more attention to rudder position after use.


some quick Defn:
"COG" stands for Course Over Ground, which is the resultant (straight line) direction between any two points on a vessel's track.

"SOG" stands for Speed Over Ground and represents the actual speed of progress with respect to the earth. It is measured by satellite receivers and is free from the effects of sea currents.

"The day and night cycle in the Lofoten Islands, Norway varies by season due to the archipelago's location above the Arctic Circle:

Midnight Sun
From the end of May to mid-July, the sun is above the horizon for 24 hours a day. This period is known as the Midnight Sun. The best places to view the midnight sun are on the coastline or mountains with a clear view to the north.

Polar Night
In the winter, the sun doesn't rise at all for some time during the polar night. The landscape is bathed in a deep blue color during the "blue hour", which occurs around 1–2 o'clock in the afternoon.

Other seasons
In between the Midnight Sun and Polar Night periods, there is a big variation between days and night depending on the season. For example, in mid-September, there are about 13 daylight hours, compared to 5 in mid-November."

Here is a great tool to find where the sun is at any given time and place, and can be used to find where and when sunrise and 'sunset' occur in the Lofoton Islands.
https://www.sunearthtools.com/dp/tools/pos_sun.php

Telling time and position before clocks:

People would rely on nature to give them cues, leading to the use of sundials and later time measuring devices like the water clock and hourglass.

The eight phases of the moon:
To tell time by the sun and moon, you can use the moon's position and the time the sun set to calculate an approximate time:
Note the time the sun set.
Note the moon's position in the sky.
Add the number of hours for the moon's position to the time of sunset.
For example, if the sun set at 7 PM and the moon is halfway across the sky, the approximate time is 1 AM.
You can also tell time by the moon during a full moon by looking at how high the moon is in the sky, similar to how you would tell time by the sun. However, the moon doesn't rise at the same time each day because it orbits the Earth, so this method can be complicated.
The sun's position can also be used to tell time with a sundial.

Telling time by Moon phases:
New moon
Waxing crescent
First quarter
Waxing gibbous
Full moon
Waning gibbous
Third quarter
Waning crescent:
The moon's phases repeat every 29.5 days. The moon's phases are caused by the different amounts of the moon that are illuminated by the sun as seen from Earth. The terms "waxing" and "waning" describe whether the moon's image is growing or shrinking. The moon goes through between 12 and 13 lunar cycles in a year because the moon's revolution around Earth is shorter than Earth's revolution around the sun.
Note: It took 18 years of constant study to create the lunar ephemerides and realize the moon had a repeating 18 year cycle of movement. Used for the Lunar distance method of navigation.
------------------------------------------------------------
So what does knowing what time it is have to do with navigating?
Well we all know what time it is depends upon where you happen to be in the world.
More precisely, what longitude. High noon may be earlier or later everywhere else due to earths rotation. So having a reliable clock that tells you when noon is at the place you left,
and comparing the time of noon at the place you are, can tell you what 'slice' (longitude) of the world you are in.
------------------------------------------------------------
Telling time by Jupiter's moons:
Galileo's discovery
In 1610, Italian astronomer Galileo Galilei discovered Jupiter's four largest moons: Io, Europa, Ganymede, and Callisto. He noticed that their positions were predictable and their periods were regular enough to be used as a celestial clock.
How it works
The moons create a cosmic clock with four hands. When the moons cross Jupiter's face, they create shadows that are visible in telescopes. The shadows are most commonly seen for Io, which orbits Jupiter every 1.8 Earth days.
Use in navigation
Galileo's method was used to determine longitude at sea, which was a vital requirement for ocean navigation at the time. However, it was difficult to observe the moons from a moving ship.
Other uses
The method was also used for surveying and mapping on land.

The sextant:
Before the sextant, there were more primitive variations. (a very good article on this is at
https://www.martek-marine.com/ecdis/pre-ecdis-navigation/
A sextant is a naval instrument that uses the sun to determine a ship's position:
How it works
A sextant measures the angle between the sun and the horizon to calculate a ship's latitude and longitude.
The sextant has a graduated arc, a movable arm with a mirror, and a telescope. To use the sextant, you line up the telescope with the horizon and move the arm until the sun reflects into the mirror and appears to be on the horizon. You can then read the sun's angle from the arc.
History
The sextant was invented in the 1730s by John Hadley and Thomas Godfrey, but its origins can be traced back to an unpublished work by Isaac Newton in the 1600s.
Still used today
Although GPS is reliable, sextants are still used by private yachtsmen and long-distance cruisers. They are also considered an essential skill for small cruising boat crews.
Before the sextant, sailors used the mariner's astrolabe to determine a ship's latitude by measuring the sun's altitude at noon.


First mechanical clocks:

The first mechanical clocks were built in the 13th century in Europe, and were tower clocks that used weights to strike bells to indicate the time.
The world's first mechanical clocks are thought to have been tower clocks built in the region spanning northern Italy to southern Germany from around 1270 to 1300 during the renaissance period. These clocks did not yet have dials or hands, but told the time by striking bells.

Revolution in determining ships position at sea:
Marine chronometers were unavailable until the late 18th century and not affordable until the 19th century.
John Harrison (3 April [O.S. 24 March] 1693 – 24 March 1776) was an English carpenter and clockmaker who invented the marine chronometer, a long-sought-after device for solving the problem of how to calculate longitude while at sea.

The longitude problem was a centuries-old challenge for sailors to accurately determine their ship's east–west position (longitude) while at sea. Without a reliable way to calculate longitude, sailors were forced to guess and steer by instinct, which often led to ships sticking to safe routes.
The longitude problem was difficult to solve because:
Inaccurate clocks:
Clocks were not reliable enough to keep time accurately on a moving ship, where factors like temperature, humidity, and motion could affect timekeeping.
Based on time difference:
Longitude is based on the time difference between a ship's current location and the location where the voyage began.

edit:
Paraphrased from the book "Longitude" by Dava Sobel

'John Harrison's clocks were made almost entirely of wood, gears included. The clock never needed lubrication because the parts that would normally call for it were carved out of 'lignum vitae' a tropical hardwood that exudes it's own grease. A clock without oil at that time was absolutely unheard of.
Harrison studiously avoided the use of iron or steel anywhere in the clockwork, for fear it would rust in the damp conditions. Wherever he needed metal, he installed parts made of brass.

His clocks were accurate up to a single second a month - while the finest quality watches produced anywhere in the world at the time, drifted off by about one minute every day.
John and his brother James were mere country bumpkins compared to the premier clock makers of the time, such as the masters Thomas Tompion or George Graham, who commanded expensive materials and experienced machinists in the clock centers of cosmopolitan London.'

Although John deserves full credit - they were essentially, the 'Wright' brothers of their time.


Using John Harrison's sea clock with the below understanding created the revolution that brought sea navigation from instinctive art to a more verifiable science.
The prime meridian, which runs through Greenwich, England, is the line of 0 degrees longitude. The antimeridian, which is 180 degrees away, is the basis for the International Date Line. The International Date Line does not follow a straight path, so it can be more or less than 180 degrees in some places.

Longitude is given as an angular measurement with 0° at the Prime Meridian, ranging from −180° westward to +180° eastward.
Earth rotates 360 degrees in 24 hours, so it rotates 15 degrees per hour. To calculate how many minutes it takes to rotate 1 degree, you can divide 60 minutes by 15 degrees, which equals 4 minutes per degree.
This also means that each time zone covers 15 degrees of longitude.

The distance between longitude lines varies depending on how far you are from the equator:
Equator: One degree of longitude is about 111 kilometers (69 miles).
60 degrees north or south: One degree of longitude is about 56 kilometers (35 miles).
90 degrees north or south (poles): One degree of longitude is zero.

Found these vids that actually show some of John Harrison's clocks and their evolution.
In addition to a more granular explanation of the longitude problem, it delves into the other competing personal and political interests of the time. The obstacles that thwarted Harrison (almost at every turn) in bringing his mechanical miracle to recognition is truly remarkable.
Had Harrison not triumphed, it is most likely our technology would not be near as advanced as it is today.

https://www.youtube.com/watch?v=zlRxWJ_kGEA&ab_channel=Drachinifel

https://www.youtube.com/watch?v=T-g27KS0yiY&ab_channel=leedsmuseums

https://www.youtube.com/watch?v=JHUNJg4boiU&ab_channel=IDGuy

SAS has a very powerful navigation tool that that would've been the envy of every sailor less than than two hundred years ago. The simple binoculars we take for granted today - and probably rarely use, would've been a priceless lifesaving invention for them.
To see land or some landmark to navigate by was always a comfort to any sailor at sea - now he could explore further out, see danger from a safe distance and more easily find home.

Some history:
https://ageofsail.wordpress.com/2008/12/12/naval-telescopes/#:~:text=Though%20telescopes%20have%20a%20long,vital%20element%20of%20seafaring%20equipment.

Skomvaer Lighthouse from kari-Anne pa Rost(TV series 2017)

Lighthouses are symbols of hope and good fortune.
Many a sailor took relief at the sign of a lighthouse light in the distance as they would return from a long voyage at sea.
They represented political power as well as technological prowess wherever they were constructed.
Often built to lay claim to a port or territory and allow safer passage for shipping and colonists.

The days when lighthouses were considered among the heights of scientific achievements are now merely 200 or so years behind us. Many have managed to stand the test of time and are still in use today. Others have become museums - that still function as lighthouses but have become automated, requiring only periodic maintenance visits. (hoping SAS will model that :)

LED technology now replaces many of the original Argand lamps that ran on whale oil or kerosene.
Many lighthouses still use light bulbs (often Mercury vapour). Automated versions usually have a carousel style bulb changer that rotates a new bulb into place when the old one fails.

Such is the case for Skomvaer Lighthouse, as you may recognise from a picture in the lighthouse tour link.

As far as I have been able to determine Skomvaer Lighthouse is the only lighthouse represented in SAS. Note: There is evidence that an additional lighthouse should exist in Vaeroy (see below)

https://en.wikipedia.org/wiki/Skomv%C3%A6r_Lighthouse

Skomvaer Lighthouse info:
https://arkitekturguide.uit.no/items/show/1259

Skomvaer - The Skomvær Lighthouse Tour
https://www.day-at-sea.com/skomvaer

Some video in Norwegian showing reconstruction and views from Skomvaer lighthouse
https://arkivinordland.no/fylkesleksikon/innhold/kommuner/rost/naturen-i-rost.38011.aspx

Lighthouses in Northern Norway
https://www.tripadvisor.com/Attractions-g190464-Activities-c47-t22-Northern_Norway.html

Lighthouses of Norway: Outer Lofoten
https://www.ibiblio.org/lighthouse/norno1a.htm

Vaeroy Lighthouse
Pics
https://www.alamy.com/old-lighthouse-of-vaeroy-vaeroy-lofoten-norway-image571739931.html

https://commons.wikimedia.org/wiki/File:V%C3%A6r%C3%B8y,_V%C3%A6r%C3%B8y_-_S-1602U3_074.jpg

https://en.wikipedia.org/wiki/V%C3%A6r%C3%B8y_Lighthouse



Google Earth confirmed

This gives a whole new meaning to the term 'as the crow flies'

"According to legend, the term “crow’s nest” derives from the practice of Viking sailors, who carried crows or ravens in a cage secured to the top of the mast. In cases of poor visibility, a crow was released, and the navigator plotted a course corresponding to the bird's flight path, which invariably headed toward the nearest land. If the bird didn’t return, it was a sign that land was near."
(Excerpt from www.nationalfisherman)

In a theory first aired 45 years ago, sunstones were clear crystals which were used as navigation tools by the great Viking mariners to navigate their way during the Viking heyday of 900-1200AD, a long time before the magnetic compass was introduced to Europe in the 13h century.

What are sunstones?
Sunstones are minerals that were believed to help sailors locate the sun, even when it was hidden by clouds or below the horizon.
How did sunstones work?
Sunstones were thought to split light into two, a phenomenon known as birefringence.
Evidence
Sunstones are mentioned in written sources from Iceland, church inventories, and the remains of a ship sent to France by Queen Elizabeth I in 1592.
Research
A crystal found in a 16th century shipwreck was similar to a sunstone and may have been Icelandic spar, a clear calcite that's common in the region.
Theories
A study published in Royal Society Open Science suggests that Vikings could have used sunstones to reach destinations like Greenland, even in cloudy or foggy weather.
Skepticism
However, some academics are skeptical of the sunstone theory.
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(My own personal take on part of the 'sunstone' story: Is that it's not inconceivable a fluke natural clear calcite crystal could act like a polarising filter, the rock being so 'common in the region' might have had a unique property to reflect back or allow through a clearer image of the sky above.)
Edit: It does seem to have such properties: https://en.wikipedia.org/wiki/Iceland_spar
Also some info is in the lower link on Viking navigation and the Sunstone:
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Beacons
Vikings Fires lit on hills or high places to guide ships at sea or signal enemy approaches.

Vikings used a unique liquid to start fires.
Clean freaks though they were, the Vikings had no qualms about harnessing the power of one human waste product. They would collect a fungus called touchwood from tree bark and boil it for several days in urine before pounding it into something akin to felt. The sodium nitrate found in urine would allow the material to smolder rather than burn, so Vikings could take fire with them on the go.

Vikings also used other senses to navigate, including:
Listening to birds and the sound of waves crashing on the shore
Hearing: The Vikings could hear how close they were to land when it was too foggy to see.
They kept an ear out for the screeching of birds and the sound of waves breaking on the shore.
Smelling for signs of land life, like fires, trees, and plants.
Looking at the color of the sea and the way the wind and waves were moving.
Using the direction of a sea breeze to navigate and determine if fresh water had flowed around them.
Using the migratory habits of whales to find specific areas of the ocean.

The Vikings also used a sun compass, which was a disk with a tip that marked hyperbolas that described the sun's shadow at different times of the year.
https://ecuip.lib.uchicago.edu/diglib/science/cultural_astronomy/cultures_vikings-2.html

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Since I figured, this is likely also what vikings used, I posed the question to Google in a general way:
Does a human's hearing when underwater, act like a passive sonar device?
Yes, a human's hearing underwater can be similar to a passive sonar device:
A human diver with normal hearing can detect sounds as low as 67 dB re 1 μPa.
This is about 3.5 times higher than the threshold in air.

Can humans do echolocation?
Yes, humans can use echolocation, a skill that involves using reflected sound to
navigate and learn about their environment:
How humans echolocate:
Humans use echolocation by making sounds like mouth clicks, finger snaps, whistling,
cane taps, or footsteps, and then listening to the echoes.

Just my guess, but at sea in foggy weather echolocation could have been quite an important
talent in any viking tribe - not necessarily gifted to those with sight.

Vikings traditionally brave the colder water for swimming, they may have easily become aware of
being able to hear sounds underwater. Might this also have been used in some way like a passive
sonar device to help detect and locate whale pods?
Yes, humans can hear whales underwater, but only some of the sounds whales make are audible to the human ear.
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What allowed the Vikings to navigate the most treacherous waters on Earth?

Their longboats are fast, rugged, designed to navigate the most treacherous waters on earth.
The longboats are almost like an all-terrain water vehicle, that allows these Vikings to go further, deeper, and almost anywhere on the planet.

Discussion topic on ancient caves and viking historic sites:
https://steamproxy.com/app/1266540/discussions/0/561358509790253176/

A great link about viking lore and architecture - includes images of old viking boathouses:
https://howtorhino.com/blog/architecture-styles/viking-architecture/

Viking navigation and the Sunstone:
https://clasmerdin.blogspot.com/2011/03/viking-art-of-navigation.html

Interesting Video:
https://youtu.be/LzOJqcwbkAE

Info about the history of fishing in Lofoten
https://www.lofoten-info.no/history.htm

XLNT site for Viking history and myth info:
About viking runes
https://norse-mythology.org/runes/
The Vikings as Explorers and Settlers
https://norse-mythology.org/vikings-explorers-settlers/

https://en.wikipedia.org/wiki/Novaya_Zemlya_effect
https://en.wikipedia.org/wiki/Viking_expansion
https://en.wikipedia.org/wiki/Galloway_Hoard

Discussion: Why do some ships-boats lean inwards while others lean outwards when turning:
https://www.quora.com/Why-do-some-ships-boats-lean-inwards-whiles-others-lean-outwards-when-turning

Link to discussion of Unreal 5.3 water and foam effects:
https://steamproxy.com/app/1266540/discussions/1/4694532143495290145/