Operator #1 stated that while starting vessel #1  there was an explosion. He also stated that the vessel had not been used in about one month.

Investigation Revealed: Vessel #1 was stored on a floating dock behind the owners residence. While kneeling on the seat, operator #1 attempted to start vessel #1 and there was an explosion. Operator #1 was thrown from the vessel.  There was smoke but no flames after the explosion. It appears operator #1 did not vent the vessel before starting.
Stone Harbor