Ah, I see.
I reckon all you need is a piece of pipe, simply, to put on the handle of the wrench to extend it. We've used that solution often. If it's exactly at 90 degrees at the end it's the ratcheting socket handle (#3) what you need there, it's perfect.
Otherwise use the angle attach (#2) at the end. That'll be a pretty tough one since the nuts are on the upper side - maybe having the kayak upside down on something - to prevent the socket slipping off - and coming in from below would make it easier in that case.
There are special tools like this below, but I don't think you really need that, only a pipe to extend the handle.
Surprise, no sig. Now there is. Or is there?