Navigation in bad weather

[Tupolev]

Hi all.

I spend quite a bit of time with this game trying to find ever new ways of playing more historically, or realistically. I remember someone posting here on an old thread about the advantages we as simmers have considering navigation and "getting lost" on the open ocean.

Knowing very little about navigation on the open ocean, I'm guessing that the only real way of plotting ones exact position is use of the Sextant and taking sun shots. If the weather is overcast/stormy for an extended amount of time you'd be down to ded. reckoning and subject to drifts, etc. So basically, you wouldn't be sure of your position.

I'm not quite interested to the point of jumping into the RealNav mods, but more the implications of losing one's exact position. I guess the point of my lengthy post is purely a question to those who would know more about real navigation:

If the weather is overcast/stormy for an extended period of time and I get an in-game radio position of a convoy, would I be able to (realistically) plot an intercept with a reasonable chance of success without the sun shots?

Was there another way of fixing ones position I'm unaware of? Radio bearings from land maybe? Were the drifts and currents in open ocean enough to render ded. reckoning unusable?

Or am I just way over-thinking the game?

T

[GoldenRivet]

In reality:

If a u-boat spotted a convoy it would transmit radio beacon signals analogous to AM radio station signals, if you will, to which other u-boats could home in. situation and weather permitting the broadcasting u-boat to maintain contact of course - which wasnt always the case

additionally, u-boats, if close enough to shore could radio locate their position with a fair degree of accuracy by triangulation of on shore civilian radio stations, but in war time this was often difficult as it was rare for civilian radio stations to broadcast their call letters or other identifying transmissions to prevent the enemy from doing just that.

In horrible weather, where sunshots were not possible for several days the u-boat commander had to make his best guess as to his approximate position based on his course and speed being fairly constant and then he could plot an intercept to the known position of his target convoy. in such a situation the best you could hope for was to at least find yourself within reasonable hydrophone range of a convoy and adjust your intercept based on periodic hydrophone observations.

so yes, it is reasonable to "wing it" so to speak if it had been some time since you were last able to confirm your position and wind up reasonably close to the reported convoy. Luck had a fair amount to do with it as well i would say

[sublynx]

Originally Posted by Tupolev

would I be able to (realistically) plot an intercept with a reasonable chance of success without the sun shots?

A very interesting question (and no you can't overthink this game in this forum ).

Here's one way to look at it: U-boat war diaries sometimes mention the differences between dead reckoning and actual situations. From what I've read the differences have been quite small: from 4 to 8 nautical miles.

for example in this diary:
http://www.uboatarchive.net/KTB96-7.htm

After many days of not being able to fix one's position one might think that the error would become bigger - but on the other hand is there a reason the dead reckoning would end up always in an error to the same direction? One could also imagine that the errors would even themselves out in the long run as one day the error might be due south, the next day due north?

My suggestion is that you could edit your U-boat off the navigation screen and in bad weather find an approximate location of your boat in a convenient zoom level by centering the screen. That way you can't make a pinpoint accurate interception but you can make it somewhat accurate.

[desirableroasted]

You could, theoretically, triangulate from broadcasting beacons. But in WWII, these were small wattage and sparse. These would have been on what we call AM frequencies, which would have had short radii by day, much longer at night.. but rarely able to reach far out at sea.

As for other navigation, you used celestial navigation (which was accurate at that minute) or, if you had to, dead reckoning.

Dead reckoning does NOT average itself out. because the variables (drift, speed, navigator competence, delta drift, delta speed, delta compentence) are constantly changing. If you took 10,000 ships through the same dead reckoning exercise over say 200 nm, the group would *average* almost exactly right. Just as 10,000 stocks, as an index, will tend to follow the same macro data. But an individual boat's dead reckoning is pure luck, within the parameters, and you would have outliers all over.

(I am no pro, but I have dead reckoned in fog before GPS on yachts... it is not easy, because your fears and second guessing get into the way. An old fishing skipper told me once "Plot the best you know, and stay with it. You aren't smarter now than then."

And that is one of the things that SHIII, bless its heart, can never make realistic. Even after 10 days of constant overcast and storm, it still GPSes me to the exact meter.