I have watched many times from long distance ,on radar...they can linger for days...and beware.... the sim loves to leave behind a destroyer guarding in ambush.
Best best is to drop below a thermal and slowly cruise until you are on the other side of the "floater" from the guard. Prepare your solution on the stern tubes. Then pop up ...take him out...and get back below the thermal layer PDQ.
Usually works like a charm.....
usually...
