Go towards the blue squares. Start looking for colored smoke on the water thru your binoculars. You have to get pretty close to them. There is an icon on the HUD that is a life preserver, when you are close enough, click the icon and you will pick up the survivor. There maybe more than one down pilot so look around. As far as completing other missions, follow these instructions:
http://www.subsim.com/radioroom/showthread.php?t=111509