Sounds like your loving the dream imagine all the places you'll be able able to work your dog up n down the miles of canal and nobody be any the wiser lol
As for feeding id have a sack of dry on the boat handy but if its just the one dog I'd be going down the route of home made it won't cost you much at all hand full of rice bit of bread bit of veg bit of meat squirt of salmon oil odd egg your leftovers etc..