How often do you use the hydrophone?
 

I mean when you are looking for targets.I have the 3 hours rule while i am on diesel engines (10-12 knots).I submerge to 15-18 meters,stay there for 3-4 minutes and then up again.

It is a good rule, very productive. Unfortunatly not very realistic. I use MEPv3 mod that let me see 20km around my boat, it's more realistic then making hydrophone check every few hours.

I read somehere 25m depth is was optimal to hear sounds, but I don't know the game can reproduce this.

Every 30 km, that being somewhere close to the maximum detection range of my sonar.

Well, 20km of vision is very unrealistic... the distance to the horizon is only about 10km from a VIIC conning tower. However, objects over the horizon can be seen, of course, but 20km is a lonnnng way.

The game doesn't worry about depth... once you are submerged, at any depth, your hydrophone man can do his stuff. The results are the same whether at 25 m in calm seas, or periscope depth in a storm.

You right. you can't see a ship above 10km but smoke. So it is realistic.

I did some calculations on this some time ago:

http://www.subsim.com/radioroom/show...7&postcount=27

Thank you:rock:

No point for doing so unless in navy fog. Will take a lot of playing time. Only advantage might be that the patrol days will be shorter since you might find targets faster and so run out of fish faster then... Just sailing and only dive when needed or thought to be wise. This might pass you some targets, cost you a bit more time to use your fish but the game play will be much faster with the same tonnage as result.

When to dive, fog, air cover, crew fatigue.

Not true. For a 2-meter tall man standing on a 2-meter platform, the horizon is only 8 km away. But if the ship he's looking for has a mast height of 30 meters then the lookout will be able to see the ship at a distance of 19 km. A battleship with a mast height of 60 meters will be visible at a distance of 26 km. And that's not smoke, that's the masthead.

True, especially in the mediteranian were visibility is double compared to the Atlantic in normal condition. But I. Any case, comparing to my own RL experience (on sailing yachts) one can see a ship @ 20 km in good weather conditions.

A short article on U-boat hydrophone listening ranges:

http://www.uboataces.com/hydrophones.shtml

Most excellent!

Bah... you might see an oil rig at 20km from a yacht in excellent conditions.

I sail and I also live on a cliff (18m) overlooking the Baltic. I watch ships every day (16 ferries, plus other merchant traffic). With a good scope, I can see ships 20-23km away, but they will be hull down and the light/conditions have to be very good.

There is a wind turbine farm about 40km away... I can make out their aircraft warning lights on a good night, and their wings in perfect light.. but these things are huge (and tall).

And I am way higher up than any yacht deck (or U-boat conning tower).

As to the question of how often I use the hydrophone, In clear weather (in type II, VII, IX) I'll rarely dip for sound checks. But at night or inclement weather, I'll dip every hour or so, depending on how bad it is.

In the type XXI I'm playing now, I rarely ever surface, just running at snorkel depth. Since it's 1944, I really get jittery running on the surface anyways. Yeah, On the rare occasion, a patrol plane will see my snorkel and bomb me, but they have always missed the first run, and dive rate from snorkel depth is so fast that my engine crew dont even get the motors back up by the time I've started to level out at crash depth. Especially with all the merchants outgunning most destroyers (it seems) now, I have no inclination to run on the surface for attacks.

Very nice!

About gargamel his remark on the snorkel; how is the hydrophone while running diesels submerged/ while using the snorkel?