overflow

My boat never had a water fill, and I'm tired of lifting up the cushions and bringing a hose into my boat in order to fill up the fresh water. The issue is really the vent where the water will overflow. Currently the tank vents to the cockpit locker. I guess the ideal option would be to plumb...

While servicing my engine this week I got to looking closely at the coolant overflow reservoir. This has always been empty and I assumed it was for expansion should the engine overheat. I keep the water level at the manifold just below the lip at the cap. The cap on this bottle is a make shift...

During the gloriously hot weather on Sunday my fuel take overflow valve started to leak diesel. I filled her up end of season last year when it was pretty cold out but I would not expect expansion enough to overflow the tank????