I'd opt for a reinforcement block of wood there, 3-4" long and 1-2" high, probably a piece of scrap okoume, epoxied to the underside of the deck after you glass or tape the underside. Then glass or tape over the surface of the block and seal all edges with epoxy, possibly a small fillet and round edges with sanding. If you could get the edges faired down enough you could put a patch of glass entirely over the extra wood. Pass a SS u-bolt through this with some type of sealant--not silicone (maybe sikaflex or marine goop)--on the threads of the bolts. You could also get a small rubber o-ring from the hardware store, or rubber washer to fit your bolt. Even if you did no sealing, not more than a few drops would get in if your holes are tight. People have also cut gaskets from bicycle inner tube rubber before for stuff like this. Drill the holes larger, fill with thickened epoxy, redrill holes to fit. A ratchet wrench an extension on the handle (PVC pipe?) would allow you to tighten the nuts from the rear hatch access if you couldn't reach them otherwise. There are various ways you could make this fitting. If you don't like the idea of a SS u-bolt raised on the rear deck, you could make a "Maroske" fitting here, or fabricate a recessed fitting.

Or, you could just skip the stern carry toggle altogether. I'm of the school of thought that says you need perimeter lines bow to stern for hanging onto a boat if you swim, and for rescues, and that the bow toggle ought to be a monkey's fist knot or some other rounded non-finger mashing type in case you are holding to it in surf and the boat does a crocodile death roll on you. A single line or closed loop on the bow toggle, not an open loop is the safest. In such a situation you're not going to want the rudder that close to your head and shoulders anyway.

I also believe that when you carry a sea kayak with two people, especially a loaded one, it should ideally be cradled under the arms--the smooth keel line makes a comfortable place to grab onto and it is very secure with no chance of stressing a fitting. But make your fittings strong anyway.

If you install a stern toggle in front of the rudder, you can tie a short piece of bungie to it and then to a deck fitting or cross-deck line--this will keep the toggle laying flat and out of the way of the rudder, but still make it useful as a carrying handle--the bungie will stretch to allow the toggle to go vertical.

Hope this helps!

: I am currently building 2 Pygmys which shall be outfitted with rudder and
: grab loops. The bow loop is not an issue, but the stern one.

: The usual position for a loop (close to the stern and through the epoxy end
: plug) is interferring with the rudder in the up position. A suitable place
: would be infront of the rudder blade tip. But now the loop has to be
: mounted through the deck, and i have stroung doubts about design strenght
: there.

: Do i need extra strips of bias cut glass from the deck to the hull?
: Reinforcement plates to increase stiffness?
: Shall the hatch reinforcement be used as stiffener and force distribution
: ring?
: Maybe carbon is needed?
: How to make a water tight mounting?

: Currently the deck is not even wired togehter, so i am open for all options

: Any helpful expertise from your side?
: What solution have you chosen?
: What would you do different from your todays perspective?

: Best thanks from Austria

: Joerg