So my plan is to put this marine Oldsmobile 350 with Berkly Jet pump into my Triloboat. I don't need a 250Hp motor, but it was a fraction of the price of a 25Hp outboard and draws less water. Besides, if I ever want to pull a log off of a beach like Relic in the old Beach Combers series, this is just the motor I need.
So here is the hatch frame, the large opening is just larger than the engine itself, and the smaller hatch behind is over the pump, which needs to be accessible to push the weed grate (Black handle) or to open the port into the pump itself to remove debris (rope is infamous to be sucked up by a jet pump in my reading)
There is a space aft of that hatch, which will end up under the bench seat. This is where I will put my little generator, a Yamaha 2400 with an aftermarket propane kit (it will run on gasoline or propane now)
Another view of the same stuff, just a different angle. You can also see the opening for my door/stairs out the starboard aft quarter (38" from the stern to be more exact)