Puppy on Board
I realize that the last response to this thread was in October 2005 and that the puppy in question is full grown by now, however, I have some experience with dogs on board and thought others might be interested.
I have lived aboard two boats for a total of approximately 4 years, first with one black and white springer and one english setter (plus wife) and secondly with two english setters (wife and two children). When we first get a puppy, we teach them a command to do their business. In our case, we use "go to it." So everytime we walk the puppy, we do two things: we praise him for going on the grass and not the carpet; and we say "go to it" several times so that these easy to hear words are linked with good behavior.
This method has worked well for all 4 dogs. Even in heavy waether during overnight passages, the dogs are able to relieve themselves.
Hope this helps.