Just so nobody thinks I'm a scroogy ol' grouch, there is ONE technique we have found that works with an R/C boat. I am NOT "Mr. Negative"

Attach the fishing line from a Rod and Reel to the boat. Drive the boat past the plane and make a broad sweeping "U" turn behind the plane.

When the line catches the plane, use the fishing reel to pull it in. THe Boat driver can pull, too, but he should stay far enough from the plane that he still has maneuvering room. If the boat has a problem, it is still retrieved by the fishing reel.