CRUISING WITH DOGS
We had the same problem - the dogs did a great job of training us to row to shore twice a day. We finally went to a pet store and got some puppy training pads that were scented with dog urine and put them on the foredeck. That and a 3 day passage is what it finally took to break their habit. Almost everyone we talked to had to wait 3 days before their dog would finally go. If that fails, I know of one boat that had a 2'' X 2'' X 4" box that they grew grass on. It worked!