Fluid makes a Solo Exp that has a bulkhead-sealed rear compartment with a hatch. it's a creeker so plenty of volume there and i've used it to do many overniters. lots of space to pack, completely dry rear bulkhead with an easily removable hatch, plenty of room for comfort, room directly behind the seat and in front of the bulkhead to store stuff for the day including rescue gear, and it actually surf ok for a creeker. on a grand self-support, you're going to store stuff in front of your foot brace and behind the seat.
To air is human, to get big air divine.