For sailing dogs. They seem very happy onboard, have great stability and move easily on deck.
For Craig, any of the smaller breeds(maybe you've had experience) have a higher energy level than most bigger dogs like Labs and Goldens, etc. You have to know what you're in for there. Jack Russells require a lot of excercise to get the most out of them. But any dog needs that and we combine the dogs needs, walking and hiking, with our sailing.
There's no denying the smaller dogs size is very handy on a boat. Doesn't that go for everything on a small sailboat?