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Old 05-21-2016, 01:57 PM   #11
acrosome
 
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Default Re: [Basic] Skill of the week: Navigation

I agree that tree moss et al isn't Navigation skill. It's Naturalist or Area Knowledge. And, frankly, I have no problems with using the former as a complementary skill for Navigation, or the latter as a replacement. Either would, for instance, let you estimate your elevation in a mountain range because you noticed that the pinyon/juniper forest is gone and now you're surrounded by Ponderosa pine. And knowing your elevation is a big clue in orienteering.

Area Knowledge must be treated as a /TL skill, too. Area Knowledge (American West)/TL8 probably includes the knowledge that I-25 is the north-south highway east of the Front Range, but not how to follow the Purgatoire River to shortcut the Santa Fe Trail. That's /TL5 or 6...

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Originally Posted by weby View Post
That is not true at all except for two specific locations on the earth(Near the actual magnetic poles). Any good orienteering map will have a compass correction marked on it, it is part of basic orienteering skills to use it. The big problem is of course that the pole moves and pretty fast so if you are in North of Canada and have an old map...
I'll back this up. I'm a zealous backcountry backpacker and I've used a compass just fine at higher latitudes that 60N without any issues at all. Any decent map will include a declination for your compass. You have to be damned close to the magnetic pole to be problematic, though the older your map the greater the likely error in the declination formula it cites.

Last edited by acrosome; 05-21-2016 at 02:04 PM.
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Old 05-21-2016, 02:54 PM   #12
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Default Re: [Basic] Skill of the week: Navigation

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Originally Posted by acrosome View Post
Area Knowledge must be treated as a /TL skill, too. Area Knowledge (American West)/TL8 probably includes the knowledge that I-25 is the north-south highway east of the Front Range, but not how to follow the Purgatoire River to shortcut the Santa Fe Trail. That's /TL5 or 6...
That's really not /TL so much as /time period, or to more fully generalize /society. It's always been the case that Area Knowledge refers to stuff that's of contemporary relevance, not necessarily the same as the stuff that would have been vital Area Knowledge centuries (or even decades) earlier in the exact same place.

This isn't typically a problem, but if time-displacement of some sort is going on it makes sense to note when as well as where your Area Knowledge is from. If there are multiple overlapping but largely separate societies in the same place and time (humans and talking animals, or faeries, or vampires...or in some cases European settlers and natives), I think it would be good to notate which one you have Area Knowledge for. In a city or neighborhood, human Area Knowledge will tell you about businesses, criminal activity, government offices, and the like...Rodent area knowledge will tell you about prominent cats in the area, what regions are exposed to hawk attacks, and where the best garbage is found, but probably won't help you get to the DMV...or at best will do so at a much larger penalty than the human version.
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Old 10-09-2018, 04:32 AM   #13
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Default Re: [Basic] Skill of the week: Navigation

Hyperbolic Navigation is a TL7 radio navigation technology that's gradually replaced by GPS at TL8. There's no mention of it in Basic or High-Tech that I can find. As far as I can see, it gives a bonus to Navigation like GPS, although this requires familiarity with the receiving equipment, and maybe an Electronics Operation/TL7 (Sensors) roll.
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Old 10-09-2018, 05:37 AM   #14
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Default Re: [Basic] Skill of the week: Navigation

Nor does it mention, let alone discuss, the use of radio direction finding in navigation, a big thing at TL6-7.

And, while we're here, for some reason you didn't mention DF16: Wilderness Adventures, which has many uses for Navigation, and interesting possibilities on failures.
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Old 10-09-2018, 06:15 AM   #15
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Default Re: [Basic] Skill of the week: Navigation

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Originally Posted by Curmudgeon View Post
There are a few odds and sods based in reality that I've thrown out from time to time that throw a spanner into the usual GURPS defaults for my players.

1) Any orienteering above 60°N (or below 60°S) cannot make use of a magnetic compass, but can resort to using an astral compass with ephemeris tables (essentially a land-going sextant with astronomy tables). This switches them from Orienteering to Navigation.

2) In pre-1970 settings, many maps of the north at 1:250,000 scale are blank sheets of paper with a grid system superimposed, i.e. they are featureless. Post-1950, they can make use of inertial navigation systems which give distance and direction from the starting point but require an accurately known starting point to know exactly what your current position is.

3) There is one supposed real-life navigation critical failure that I did manage to use in one game. I'll use the original anecdote though:
Naval midshipman (on a ship in the Pacific theatre): Here are my calculations for our position, sir.
Captain (after perusing the calculations): Young man, kindly remove your headdress.
Midshipman: Sir?
Captain: Young man, we are on sacred soil. By your calculations, we're in the middle of Westminster Abbey.
3) I have heard the same, except with St-Pierre of Rome instead of Westminster. Absolutely sure it was in one of the Tintin comics (Rackham ?), but it is likely older.

Sorry, but 1) and 2) are mostly false, as said above.

1) by personal experience hiking in Scandinavia. Granted, using an old map could be a problem.
It is true near the Poles, and truer (more true ?) in areas where the angle between real and magnetic North is more apparent.

2) see for example http://legacy.lib.utexas.edu/maps/ams/finland/

it was definitively true before satellite mapping for remote part of Siberia , Antartica and Arctic Ice fields, but definitively not so for Europe, and likely not for Canada.

----

I have followed courses in Land and Sea navigation (both before GPS became common, although they already existed) and have a default in Air navigation from playing Flight Simulator.
GPS in all case is a game changer. a +3 bonus is probably understated.

With modern instruments and maps, you usually have such bonuses that you only need to fear the automatic failure/critical failure roll as long as you have minimal training. Still, it happen quite often !
With map/compass/astral reckoning/radio navigation ... failure will happen even to trained peoples, especially in low visibility and lack of area knowledge.
With only the raw skill .. that's when the fun start :)

I would give a huge bonus to navigation to anyone who have relevant area knowledge.

I also suggested optional sub-specialties for land navigation : urban navigation and car navigation. It could also be hyper-specialization perk or familiarity, but it definitively represent existing peoples.

Last edited by Celjabba; 10-09-2018 at 06:37 AM.
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Old 10-09-2018, 06:39 AM   #16
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Default Re: [Basic] Skill of the week: Navigation

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I have followed courses in Land and Sea navigation (both before GPS became common, although they already existed) and have a default in Air navigation from playing Flight Simulator.
GPS in all case is a game changer. a +3 bonus is probably understated.

With modern instruments and maps, you usually have such bonuses that you only need to fear the automatic failure/critical failure if you have minimal training. Still, it happen !
With map/compass/astral reckoning/radio navigation ... failure will happen even to trained peoples, especially in low visibility and lack of area knowledge.
With only the raw skill .. that's when the fun start :)
The problem with GPS for land navigation is that while it'll tell you where you are, and plotting a course on a map has never been hard if you know that, it doesn't help in the slightest with map interpretation, relating map to ground, or reading the ground, and these are the common failure points in land navigation and movement.

"How can you tell a inexperienced officer?"

"Because his routes are straight lines defined by compass bearings."
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Old 10-11-2018, 01:25 AM   #17
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Default Re: [Basic] Skill of the week: Navigation

Something that gets ignored for lower TL versions of Navigation is degree of accuracy, especially in the absence of known landmarks.

Before TL6, marine navigators were doing their job right if they could get their ship within ~20 miles of their destination.

At TL6/early TL7, marine and aerial navigators were doing a great job if they could get within ~5 miles of their destination.

Under less than ideal circumstances, it is also easy to mistake one landmark for another, assuming that you can see landmarks at all.

For example, during WW2, it was not uncommon for high altitude bombers to get lost and accidentally bomb the wrong target, or even the wrong city! (e.g., the USAAF accidentally bombed a Swiss town rather than a German one.)

Darkness penalties should apply to most forms of pre-TL8 Navigation, as should penalties for relatively poor visibility.

Having multiple people make Navigation skill rolls is realistic, but it requires a complete set of equipment - and sometimes a dedicated crew station - for each person making the attempt.

There's also the problem of whose Navigation do you trust? The GM should make Navigation rolls in secret, potentially setting up a situation where one navigator is right and the other navigator is wrong. If the navigator who is wrong is the ranking officer, tragedy can ensue.
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Old 10-11-2018, 02:09 AM   #18
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Default Re: [Basic] Skill of the week: Navigation

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Originally Posted by Celjabba View Post
3) I have heard the same, except with St-Pierre of Rome instead of Westminster. Absolutely sure it was in one of the Tintin comics (Rackham ?), but it is likely older.
I
It's Westminster Abbey in the English translation; It is indeed in Red Rackham's Treasure
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Old 10-11-2018, 07:14 AM   #19
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Default Re: [Basic] Skill of the week: Navigation

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There's also the problem of whose Navigation do you trust? The GM should make Navigation rolls in secret, potentially setting up a situation where one navigator is right and the other navigator is wrong. If the navigator who is wrong is the ranking officer, tragedy can ensue.
Exactly such a conflict takes place in Heinlein's Starman Jones.
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Old 10-11-2018, 08:01 AM   #20
Celjabba
 
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Default Re: [Basic] Skill of the week: Navigation

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Originally Posted by Pursuivant View Post
Something that gets ignored for lower TL versions of Navigation is degree of accuracy, especially in the absence of known landmarks.

Before TL6, marine navigators were doing their job right if they could get their ship within ~20 miles of their destination.

At TL6/early TL7, marine and aerial navigators were doing a great job if they could get within ~5 miles of their destination.

Under less than ideal circumstances, it is also easy to mistake one landmark for another, assuming that you can see landmarks at all.

For example, during WW2, it was not uncommon for high altitude bombers to get lost and accidentally bomb the wrong target, or even the wrong city! (e.g., the USAAF accidentally bombed a Swiss town rather than a German one.)

Darkness penalties should apply to most forms of pre-TL8 Navigation, as should penalties for relatively poor visibility.
There are several airliner pilots who landed at the wrong airport as recently as a couple year ago. So even TL8 navigation aid won't prevent all mistakes. :)
Poor visibility would actually be a bonus to navigation in those cases : the errors usually happened because the pilot saw *a* landing strip and landed on it ignoring the GPS/VOR/... telling them they were 20+ km off target.

In my opinion, the biggest cause of navigation error, at least among trained people with actual skill, is fatigue.
I can attest from personal experience that if you are dead tired, you will make idiotic navigation mistakes even when GPS, Compass and map tell you you are wrong.
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