sitting on the bottom

[High Voltage]

If you can rest on the bottom -------

YOU'RE NOT DEEP
ENOUGH!!!!

[Iron Budokan]

What about running shallow? At the beginning of the war the sub commanders used to run at periscope depth to evade DDs because they knew their listening gear couldn't operate at that angle. Is that modeled?

[Corrupt_File]

Originally Posted by Iron Budokan

What about running shallow? At the beginning of the war the sub commanders used to run at periscope depth to evade DDs because they knew their listening gear couldn't operate at that angle. Is that modeled?

From experience, I'd conclude no...

[Eagle Eye]

They've always heard me at periscope depth. I've learned my lesson about hunting convoys in shallow waters.

[johnno74]

Active sonar "pings" are actually reflected by density changes - they don't bounce back towards the sender from your hull, they bounce back from the air space inside the pressure hull

So, in reality, sitting on the bottom shouldn't help you evade active sonar.

[ref]

Originally Posted by Eagle Eye

They've always heard me at periscope depth. I've learned my lesson about hunting convoys in shallow waters.

Most people keeps confusing sensors, the early sonar is less effective because it's cone is pointing a bit down, but don't forget that the ships also has hydrophones which aren't limited in its angles, thay can pick you on passive by listening to your engines.

Ref

[Keelbuster]

Originally Posted by Iron Budokan

What about running shallow? At the beginning of the war the sub commanders used to run at periscope depth to evade DDs because they knew their listening gear couldn't operate at that angle. Is that modeled?

This can be quite effective. In medium sea states, you can achieve some stealth by riding at PD. I always begin my evasion at PD, and I only dive if i have to. Visual information is so rich that I always prefer to keep it. When you see them go into their attack run, you can go flank and break right or left, and they often won't hit you with their DCs. You can see which way they turn, and plot a flank evasion course. If necessary, you can take a shot at them (zero gyro, mag pistol). And, if I have to dive, i don't like to go below 40m: i like to be able to see my attacker's course on the surface through the observation scope. THis makes my DC evasion easier. The only time I would go really deep is if a) there's no bottom and b) there are many attackers and no other way out. With 1 or 2 attackers, PD is a good place to be. The other thing is that diving saps speed - by going down to 150m, you waste velocity that could have been spent gaining lateral separation from your attackers. Finally, I like to 'spend' depth during evasion. For instance, in the first DC run, maybe the attacker knows you are at PD, so he sets his charges for min depth. In the evasino run, you drop to 30m and he misses. In his second run, he knows you're at 30, so you drop to 60. In the third you drop to 90, etc. If you drop all the way to 150 in the first attack, you've got nowhere to go but up! Also, if you get hit at that depth, you might just pop. So - my feeling is that you should use depth sparingly. Maybe I'm drifting OT now?

Kb