If it ain't broke, don't fix it.
But if it is...?
- Waterproof to above the knocked-down waterline (should float on its side without shipping water).
- Long gangway running the length of the interior (mid-line security for standing crew).
- Self-rescuing from inside the hull (!).
- All operations possible from within shelter (no outside cockpit necessary).
- Easily stricken rig (to reduce windage for rowing).
- Reasonable performance under oars (eliminates expense, and weight of motor, and allows extended cruising away from fuel sources).
Bend a 45deg, angled section at the oar's fulcrum, offsetting the inboard loom from the outboard by enough to clear the hull and your chosen lock hardware. Boot the oar outboard (raingear sleeves?) to waterproof and retain the oar from sliding out. Stowage can be arranged using single-horn cleats for blade and grip, with bungee tie-downs.
Oar Boots can be affixed around a lipped oar port opening, similar to a kayak skirt lip.
A stiffish rubber sheet, close fit around the oar would make a pretty fair lock in this situation.
BTW, TriloBoats has a new, BIRDWATCHER inpired offering, the T20x4 SCUTTLEFISH.