If the boat radio has been switched on before the transmitter, the winch servo might well have stalled itself and died. This is unlikely to happen to the steering servo as power levels are much lower. Personally, I would have opted for one of the new drum servos with the shrouded drum (same size as a standard servo), and just used it single ended to keep things simple. Probably a fraction of the price, as well. Certainly much more compact, and the problem might well change, depending on the type, to one of too much travel.
While information in books is often good, when you start looking at modern technology, it advances so quickly that book information is often outdated before it gets printed.