Is something wrong here??

[bigboywooly]

If they lose contact with you for 30 minutes they will go away
As they still have some form of contact they are still there

You werent alone though

Far above, Walker was talking to his officers: "No doubt about it. She's gone deeper than I thought possible, and our depth-charge primers won't explode below 600 feet. Very maddening indeed." He grinned and continued: "Well, long wait ahead. Let's have some sandwiches sent up. We will sit it out. I estimate this chap will surface at midnight. Either his air or batteries will give out by then." It was shortly after noon on June 13. By 8 p.m. Poser had taken several evasive turns without result. He could not shake off his tormentors. At two minutes after midnight his air gave out. He ordered reluctantly, "Take her to the surface." Without any audible warning, U-202 rose fast through the water to surface with bows high in the air. Her crew leaped through the conning tower hatch to man her guns, and Poser shouted for full speed in the hope of outrunning the hunters. On Starling's bridge, the tiny silver conning tower was visible in the moonlight. "Star shell...commence," ordered Walker. One turret bathed the heavens with light. Then came a flashing crash of the first broadside from all six sloops laying a barrage of shells around the target. A dull red glow leaped from behind the conning tower of the U-boat. A dimmed lamp blinked from Starling, and firing ceased while Walker increased speed to ram.

12 hours sat above the uboat

http://www.mikekemble.com/ww2/walker.html