IOf you heard something they know you're there already

youre fucked

Which certainly they would be aware of from intelligence

If your just slowly

Well you better think of everything else that makes a surface ship loud

Undamped pumps

People talking

People moving

Water flowing in the shi

Air con fans and condensers

I'm not denying warships and ships in general are loud

A sub has designed these things almost out

ALMOST

EVERYTHING is detectable..

By some means or another

Read

ALMOST

That's not in doubt here.

Thanks

So yeah

A surface ship is only detecting a sub first in a very limited number of circumstances

And they all require the sub to either be old as shit or incompetent as fuck

Or any combination thereof

As most subs are

*old*

There you have to remember that most surface passive sonar systems are less effective then their sub surface counterparts

Mainly due to self noise

And other requirements, true

They can't see behind them unless they have a towed array

Which most dont

Most subs do

They cant see behind them because of their own prop noise

Well, most modern ships have helicopters

With dipping sonar

Which are the scariest thing about them

To extend the detection range and to cover that issue right there

However they arnt deployed unless they hear the sub

and the sub can hear them

because big fucking slashing noise on water

Depends at what layer the submarine is at

If it's below the thermal layer or not