Not sure what you mean by "pod" but in the Fed-5 landsailor in your first picture, the mast sets in a cup at the bottom and a ring about a foot or two above the cup.

How about bolt a cup to the bottom of the dolphin striker and the ring to the main beam?

A landsailer doesn't go downwind (at least relative to apparent wind) - that sort of rig might need some modification for a waterborne boat.