How to bottom a submarine correctly ...

[OneShot]

If you set your depth to exactly bottom or only a meter or so below it, your sub will settle down, but eventually float back upward. Now, if you bottom your sub, THEN set your depth to something like thirty or forty meters below bottom, your sub stays on the bottom.

Make sure you bottom the sub BEFORE giving some massively deep order to keep it there, lest the thing sinks like a cinder block and you wreck something.

The problem is that the subs trim slightly positive. I guess you could call it a good thing. Better than sitting motionless for a while and ending up at crush depth. So, when your set depth and your actual depth are the same, and you're not moving, your dive planes can’t hold you down and you ever so slowly rise. By issuing a depth lower than what you're at, the boat continuously tries to trim itself down to that depth by making itself negatively bouyant. And since the bottom happens to be in the way of your set depth, you just kinda stick there.

[Driftwood]

Has anyone tested out the actual effectiveness of "bottoming the boat" (as the XO of the Red October suggested) when attempting to evade detection?

[OneShot]

I havent tested this method yet myself - as I mostly play one of the two Air Plattforms. I guess this is a question for our Bubbleheads.

[The Bellman]

A Bubbleheads response may be - 'Noted' or as Prof. Galbraith often said - "I hear you' :wink:

This is a topic that some sub players may not wish to open up here ? :rolleyes:
There are many others like the UUV in the transients SS DW forum :eek:

Experienced SC players look to their seniors to set the pace of any revelations. Many of us will naturely be a little cautious. :cool:

Like a faint 50 khz trace in NB they have seen this post, they are watching it but rest assured they are not ignoring it.:smile:

That may not sit well with my 'Freedom of information' rant - but hey life is full of contradictions.:biggrin:

[Molon Labe]

Driftwood and I just did a test. Rock bottom, seawolf sitting on the bottom, about 8nm away from LA pinging active, 45 degree aspect. LA detected the Seawolf with a weak but visible active return (and audio return). Raising the Seawolf 200 ft off the bottom did not cause the signal strength to increase.

[The Bellman]

:biggrin: :biggrin:

Thanks Molon thats very interesting. Did you carry out any passive tests ? Say your opponent is tracking via TA and you, having reeled in the TA, sit near, on, or gently collide with the bottom ? Notice any changes ?

As you know I'm temporarily unable to carry out MP testing and am therefore unable to assess the impact of 'certain' techniques.

:rolleyes: :rolleyes:

[Molon Labe]

Well, I didn't have LOS when he bottomed the sub...however I believe I have seen increased NL's from subs scraping the bottom in the past.

There was no change in passive behavior while sitting on the bottom...nor should any change be expected.

[The Bellman]

With your own TA in, I was wondering more about the effects on your opponents passive sonar
during and after the bottoming-out process.

Additionaly did you try having your opponent launch and when torps en-route to you, you gently 'hit' the bottom. (Level bottom, no seamounts,no shallows.) I'm not refering to the Blue Book ruse of 'grounding' incoming. Or detonation in the shallows (Presets)

Your investigation steps are very welcome. Thanks. :smile: