Kick-up propeller shaft for shallow draft

Hi Wroc, Could a jet unit be of any use, no protrusions, especially if you don't include a reversing bucket; can be diesel powered; and with a metal wear ring to cope with sand, shells, and gravel, although the prop will still suffer in those conditions; simple single stage pump. Not very efficient for distance motorsailing, but useful for beaching and occasional shallows. The prop will stay in the water so less cavitation issues, especially with low revs dieseling. Or you could drop in a light weight PWC jet unit and engine, supercharged with sealed cooling circuit and intercooler, if weight and space is an issue; just fuel hungry.
What barge designs do you have so far. I'd like to make / have a trailerable roomy barge style yacht; I really like the barge Juno, but it's a bit big for my purposes and single handing.
I'm thinking around 28 foot long, shoal draught, flat bottom, blunt bow, lee boards, possibly hinged transom section for loading, lug sails with masts on tabernacles, and other crazy ideas.

 

Boat design with movable (up/down) prop shaft?? https://www.boatdesign.net/threads/boat-design-with-movable-up-down-prop-shaft.61094/
Some other options

 

To be perfectly honest, for that size of boat, I'd just use a 10hp high-thrust outboard. Regarding designs, I am going simple, starting from the Triloboat concept and modifying to suit my own requirements and fancy.

 

This is what doing an SOR helps to save time and effort. You started by stating the power was a diesel from a lifeboat. That was a constraint and advice on the design was based on that. If you change the power plant to a 10HP outboard, the design will be completely different. Constraints are requirements that can't be changed and drive the design.