Certainly an outboard would give the power for maneuverablity in tight quarters as an emergency engine. The problem is that of a dual fuel supply--unless a suitable small diesel outboard is available (say 15 hp) and in a very long shaft version. I have outboards as back up power in my current boats--but you need a long shaft to keep the prop in the water--and it is subject to dousing with sea water when in heavy weather and on the bracket. Bob Austin