[TEC] Real navigation Tutorials

[Sean C]

Originally Posted by MrArt

If my time zone is GMT +1 then I must use the Nautical Almanac with a GMT -1 time, and if the time zone is GMT -5
then I have to use GMT +5 time

I'm not sure, but this may be due to the fact that there are two different conventions for naming nautical time zones.


For example: let's say you're at 60° west longitude. Some sources would label this as "GMT -4", because the time there is 4 hours before the time at Greenwich. However, other sources would label it as "GMT +4", because you have to add 4 hours to get to GMT. It's the same thing, just two different ways of looking at it.


Personally, the vast majority of examples I have seen list west longitudes as negative and east as positive. But, I have seen it the other way around occasionally. IIRC, the latter is more popular in European countries and the former in the U.S.


There was a discussion about this very topic on NavList some time ago. I'll try and see if I can find it ...


[EDIT] Here it is: Time Zone Conventions.

[MrArt]

Originally Posted by Nathaniel B.

I'm not sure, but this may be due to the fact that there are two different conventions for naming nautical time zones.

In real live you have to use Nautical Almanac with GMT time.
For example: I'm in GMT -4 time zone. So I need to uze Nautical Almanac with local time +4 (same as GMT) to find Declanation and GHA.

But in SH I need to uze GMT - time zone (at our example GMT +4). It's totaly wrong.

[MrArt]

Another example:

Today is 20 January 1943. U-Boat coordinates are 18°40'N 72°59'W. GMT is 18:01:30 and local time is 13:01:30 (GMT -5).
The sun is under horizon ¯\_(ツ)_/¯

I can observe Moon at true azimuth 73°58' and altitude 10°34'



Now go to Stellarium to the same place and the same time. But to get the same position of celestial bodies it needs to take GMT +5 time.



So in real life we have this celestial bodies position at 23:01:30 GMT and in SH at 18:01:30 GMT. It should not be like that.

It looks like Real Navigation uses GMT time as a local time.

[EDIT] It happens at initial loading. If you start mission or campaign at GMT +1 time zone you should ALWAYS subtract 1 hour from GMT time. Or if you starting point at GMT -5 time zone you should always add 5 hours to GMT. So so-called "GMT" time is local time at your starting point. I checked it with transatlantic trip.

[Lasicowaty]

Hi

I'm trying to get back to SH after few years, but first time with calculating u-boot position with real navigation. I would like to learn it from totorials #1 and #2 at first page of this thread, but I can't see the pictures. They are not available anymore. Well, I will try without pictures. But are there any other tutorials? There are many tutorials for manual TDC and all firing stuff but any tutorial about real navigation mod I can find says that your position will give you yor crew nawigator. That;ś not real navigation! There are tutorials for manual position calculating but I can't find them or there is no any but this thread only?

Cheers to all!

[Ashikaga]

@Sjizzle: can you upload your nav tutorial images again please?


OLtzS Ashikaga.

[Macgregor the Hammer]

In 1895, Joshua Slocum, the first man to sail around the world solo on his gaff rigged sloop Spray, used a cheap tin clock for approximate time, noon sun sightings and lunar distance sightings and dead reckoning to navigate.

Pretty cool stuff...........

[slipper]

Same as above really, is there any way of getting the pictures uploaded on the tutorials please? or has anyone saved them and could pm a copy?

many thanks

[Sean C]

If no one else responds, I would be happy to help with any general celestial navigation questions. However, I am unfamiliar with SH, so I cannot comment on how it works in-game.

[slipper]

Thanks, Nathaniel that's a very kind offer. I'm looking to use the sextant in SH5 really, so not sure how much or how it differs from real-life techniques.

I will have a play about and come back to you if I need some clarification.

I also just came across this series of videos

https://www.subsim.com/radioroom/sho...d.php?t=246847

have not had time to look at them yet, but they look very good


regards

[Sean C]

Originally Posted by slipper

Thanks, Nathaniel that's a very kind offer. I'm looking to use the sextant in SH5 really, so not sure how much or how it differs from real-life techniques.

I will have a play about and come back to you if I need some clarification.

I also just came across this series of videos

https://www.subsim.com/radioroom/sho...d.php?t=246847

have not had time to look at them yet, but they look very good


regards

From what I have read, it seems that Alpheratz has worked very hard to ensure that the standard techniques work in-game*. If what he writes is true, and he has developed an almanac that will work with the game, then I should be able to provide you with any help you might need.



Just let me know if you run into any stumbling blocks. A little help along the way can be the catalyst to a much deeper understanding of the fundamental concepts. (And it can also help by explaining the [sometimes outdated] jargon which often confuses the "uninitiated".) And if you really understand what's going on, the chance of making a mistake is greatly reduced.


Cheers!


* To be clear: this is not a trivial task. I'm not entirely sure that everyone here appreciates how much work must've gone into this.

[Salvadoreno]

Originally Posted by slipper

Same as above really, is there any way of getting the pictures uploaded on the tutorials please? or has anyone saved them and could pm a copy?

many thanks

I'd like to second this.

[Szut]

In case anyone is still interested to see the picture of the original post, I have uploaded a copy I did once in the link below. I do own any of this work, but made a copy for my convenience once.

https://docs.google.com/document/d/1...f=true&sd=true

Originally Posted by Szut

In case anyone is still interested to see the picture of the original post, I have uploaded a copy I did once in the link below. I do own any of this work, but made a copy for my convenience once.

https://docs.google.com/document/d/1...f=true&sd=true

Hello Szut! Thank you for subscribing to the channel!
Indeed, the Sun can be used to determine latitude in Silent Hunter 5, given the declination of the Sun SH5, which is different from the real one (requires a special SH5 almanac), as well as the sun semidiameter. I talk about these nuances in my videos.

[U-190]

Originally Posted by Alpheratz

Hello Szut! Thank you for subscribing to the channel!
Indeed, the Sun can be used to determine latitude in Silent Hunter 5, given the declination of the Sun SH5, which is different from the real one (requires a special SH5 almanac), as well as the sun semidiameter. I talk about these nuances in my videos.

Привет! Сегодня обновил файлы компаса для использования в реальной навигации. Пробовал ли ты мой компас? Правильно ли он работает?

Originally Posted by U-190

Привет! Сегодня обновил файлы компаса для использования в реальной навигации. Пробовал ли ты мой компас? Правильно ли он работает?

Привет! Я пробовал две предыдущие версии. В первой версии у меня не вращалась картушка. Вторая версия у меня работала хорошо, но я тестировал ее без реальной навигации. Сегодня проверю версию 1.3 с реальной навигацией, напишу.