Wow Dan! A dog huh?
First of all, I have had dogs on my boats for 15 years. We have never been without them.
The best of the breeds that I have direct experience with are Miniature Schnauzers. They are very affectionate and loving toward the family (kids especially). They will build a very close bond to their owners. They are smart, almost too smart for their own good. They do not shed but must be shaved/groomed. We generally groomed our own, but to each his own.
That being said, I am not sure I would want that dog on the boat again because any long haired dog always gets the stickers in their fur. For Scooter, our last Min Schnauzer, we ended up keeping his skrit really short or almost non-existent because it was such an issue. Depending on how you will use the boat/dog, this becomes an issue because they have to go to shore a lot. Min Sch's sometimes have ear problems or get Schnauzer bumps, but in general are very easy to care for. Min Schnauzers are natural mousers and will actively hunt them out. I have not owned a single schnauzer that did not catch at least one mouse. It is in their blood.
If the long hair was not a big isue for me, I would consider a Min/teacup Yorkee. I have owned one. They are great little dogs and even when they poop or pee where tehy are not supposed to, it is not a huge deal because there simply is not much there. They tend to build close relationships with their owners and can be little 'yippers', but they make a good boat dog because of their size. They can swim. They can run around the boat and still get plenty of exercise.
We currently have a big, fat english Bulldog. That is probably the worst of all boat dogs, HOWEVER: they love to just sit around so they are easy to care for on the boat. However, they snore like a freight train, belch like beer drinker, eat Wombats for breafast, pick their teeth with Labradoodles, and fart out Sailingdogs
In all sesriousness, my friend, what are your plans with this dog? Are you considering cruising? Long vacations? You know your business better than me, but cruising with dogs is tough. It sounds really easy to board them, but in reality, our dogs have really gone sullen when we leave them behind. If I could go back, I would not have bought my bulldog. Not because she is not a great boat dog, but because of the difficulties associated with any dog where we are going.
Just some thoughts, but I know you know that stuff better than I.
Here is Fatty -
Here is Sissie and Scooter. Sissie (on the left) is dad's dog. Scooter (rigth) grew up on boats and is ours.
This is scooter on his last sail. I took him out (banged up the boat doing it) for one last ride. That was his place - staring out behind us or riding in the dink. I put him down that next day. Broke my heart.