RedactedNarrative: Vessel 1 experienced an engine failure. Due to the open transom design of the vessel, the vessel began taking on more water (through the open transom) then the bilge pump could keep up with. Eventually the batteries died causing the hull to fill with water and capsize. All occupants were able to don their life vests prior to the vessel flipping. A good samaritan stopped and helped all passengers out of the water and transported them back to matheson hammock marina. Fire boat #1, captian responded to matheson but there were no injuries. Fast response unit 5 responded to the scene, righted the vessel and towed in into matheson hammock.