I've had several dogs on my boat. My beloved yellow lab was a natural on the boat. She learned it was perfectly acceptable to pee on the side decks and would go down below when the weather got snotty or when ordered to do so. She was able to jump up on deck from the dink and was always first in to the dink when a trip ashore was promised. Loosing her due to old age was painful. My current dog has half a season under her belt and is learning the ropes. She is a mutt, part black lab and part Flat Coat retriever. Generally Retrievers seem to make good boat dogs. The are generally strong swimmers so if they go over they have a good chance of survival. It helps if they are on the smaller side to drag them back aboard. In general Lots of other breeds make great boat dogs. It really just depends on the individual dog, not so much the breed.