The vessel was heading south at 35 mph, boat engine started to sputter and boat began to lose power.  A pop sound was heard and the boat stopped running.  No fire was seen, just heavy white smoke.  Operator used fire extinguisher and sprayed over entire engine.  Unknown whether or not halon system was active.  Smoke extinguished and boat would not run.  Boat towned by operator with pwc.
Antioch                       