I think just about any two way automotive type could be made to work. Just add the proximity sensor and digital tilt sensor. The lock and unlock outputs can also be made to work on the box lids with a few actuators.
Only draw back could be the moisture in the boat and the extra attention you would need to make the system last. Mount the boxes in the driest locations and solder and heat shrink every connection to protect the copper wiring.
Maybe. Motorcycle type would be a viable option?