A Doberman would probably be alright, but I don't know many that enjoy water (I know atleast 30...maybe 3 enjoy water). They also need a lot of training and socializing, as do all dogs but it concerns me a bit as I know you're having troubles with Buddy (I do understand you're working with him though!). Good luck in your search Dobermans also have sight hound bred into them, so 100% reliable off leash in an unfenced area could be a problem, but I do know plenty who are reliable.