The survivors drift with the currents. The blue square is where they hit the water, but I have found most drift either due N or S (most times the AI moves them S). Point the mouse pointer over the square and click, it will tell you the time and direction. Currents seem to run about 3 knts so for every hour beyond the time they hit the water, they will have drifted about 3 miles. The info may show motion to the N, but I've found many more of them to the S.
As said above, get to the area, look for red/orange smoke. Being on the surface increases the range of your vision, and using the binocs (now that I know how!) helps. You have to be relatively close to pick them up, and it seems you can't be going more than about 5 knots, ie, you have to slow way down. in real life, you'd have to come to a dead stop, so in a way, this is more efficient.
