[DS]

Yes, the assumption in that grid search scenario is that you started off hidden.

If we change the scenario to one where you want to hide from people who already have an good idea where you are (ie: along a certain line of bearing to a max range of x), then you can move as quickly away fro mthat line of bearing as quickly as you think you can without them generating a solution on your noise (they have current bearing, and may achieve general bearing drift and maybe even aproximate range, but try not to give up accurat range and course), then reduce noise and change course again (this time hopefully wrecking any budding fire solution they had been working on) and drift away quietly. This is essentially the manouver used to evade torpeodo launched at you that has not yet enabled - move off the bearing line, and out of the acquisition cone.

Of course, this pretty well goes out the window if the enemy is dropping sonobouys all over the area, or if you're getting nailed with active sonar as you manouver. In those cases, I think quiet, distance, and layers are probably your best bet.