I only fix I can see.....is to glue on a new one. Some of these boats are so thin in material that you would have to glue a large patch on, after you remove the broken oar lock from the boat.
Maybe you could come up with a break down paddle with a strap-on oar lock attached to it. You could strap it around the tube as one unit.
The other way might be to strap a spare paddle to the back of the boat and R1 your way to the take out. On some of the boats I've seen, the weak point is the hole drilled through the middle of the oar, thus the oar breaks in half. i don't think I've ever seen one of these boats with a spare oar or paddle strapped to it.
In the lake fishing world you have these awesome trolling motor set ups with remote foot switch and GPS tracking. Maybe you could design a rear tube mount for a remote controlled trolling motor and foot switch.