Vessel 1 was in operation with two persons on board when the Operator of Vessel 1 observed that smoke was coming from the engine compartment.  The Operator immediately stopped Vessel 1 and lifted the engine compartment to determine the source of the smoke.  The Operator reported that he heard crackling and saw a significant amount of smoke originating from the back of the engine compartment.  The Operator then grabbed a fire extinguisher and used the entire canister on the engine.  The source of the smoke was unable to be determined, but the Operator did report that this was the first "test drive" of Vessel 1 in the current boating season.
Montezuma