Roop and I were yakkin' about using crossmembers of some sort to connect yaks together and build a nice casting platform out there... that would be a kick! If nothing else a lightweight boom across yaks would allow your paddling buddy to stabilize your yak enough to climb in if needed.
I like the idea of outriggers. The pacific islanders have used them to navigate big seas successfully for centuries. I don't know why all sea kayaks don't offer a boom accessory.