This is what I have.
https://www.polycraft.com/300-tuffy
And I am using an ePropulsion with it.
With that combo I do not leave the engine on it, but rather I store it in the engine bay below the saloon. Each half of the engine is light enough to manage installation well enough while sitting in the dink. The process avoids banging it around against railings and the side of the boat and its windows while lifting / lowering. Obviously, I am carrying it up top.
Because I am not lifting with an engine, I "could" get away with 10.5 ft., or even 11. But 10 ft is plenty long.
Thought process:
1) I wanted a hard dink. Lots of rough wooden piers and bulkheads on the Chesapeake and I never felt safe bumping the old RIB I had years ago into docks.
2) I wanted the most stable dink I could find when boarding. Many are pretty skittish. Old bones are getting older. This was my #1 priority.
3) I have no need to get up on plane and zoom. The engine choice actually came first. Going in that direction, I have no gas aboard. I had already eliminated propane, so the only fuel I have aboard is diesel for the Cummins and generator.
4) Not lowering the dink with engine attached, total weight was not an important factor. Boat weight with no engine is about the same as a 10 ft RIB with 15 hp gas outboard.
5) My topside railing is full height. Some spec a lower section at the stern. I wanted full height if I, or subsequent owners, switch to carrying the dink on davits off the swim platform.
6) With full height railings, you do have to pay some attention to height of the boat from the bottom to davit crane attachment points. The issue is being sure the bottom of the boat clears the railing when lifted to full height. For me its close, but it does.
7) My #2 priority was I wanted a dink I sit *IN* not *ON*. Sitting on the side of a RIB is fine when just messing around. But using it to go in for a restaurant meal or in-town sightseeing the last thing you want is a wet butt from a splash.
This one meets all of those criteria, with the addition of the fact it has 3 storage lockers for dink anchor, and sundry other bits of gear. It is the most stable hard dink I've seen. It is pretty dry in the flat water its only seen so far. The sides are low so I do wonder how well it will behave in any chop. It is rated for 15hp engines, and it seems to fly on plane in the videos that are out there. Figuring out a lift harness took some doing, but i got there.
My #2 choice would probably have been a Whaley. I am told they don't actually plane with a 15hp despite what they say. I started by looking at a Pudgy, and while there is a lot to like, the round bottom doesn't give it the stability on boarding I was looking for.
RIBS are pretty standard from one brand to the next. Not so when you begin down the path of hard dinks. Finding the right one was hard.