An automatic bilge pump but make sure bypass main battery shutoff switch .
Ideally separate battery for auto bilge pump, but a small solar panel in windshield should keep battery charged
I would look for some kind of wax or polish to put on at start of season , that would help cut down on scum build up ??
If possible.... a game camera linked to your phone or computer attached to a tree or post...would be nice so can keep eye on it ???