The operator/owner and his family were fishing on north Puget Sound between Camano Island and Hat Island in their 20 foot cabin motorboat.  They had been out 4 1/2 hours and would drift on the tide for a while then motor back to starting point.  During one of these runs the operator went to start the engine and it wouldn't start.  He lifted the cowling over the engine and discovered the engine compartment was flooded up to the exhaust manifold.  He started his small outboard trolling motor and got the boat moving but saw the water was rising too fast.  He immediately helped his family get into life jackets, called MAYDAY on the VHF radio and shot off six distress flares.  Two boats responded and got everyone off the sinking boat.  The operator reported that the boat went down but resurfaced a few minutes later hull up.  

The boat was towed to a marina and taken off the water, and a sheriff's officer and Bayside Marine technician later examined and tested it.  Findings were inconclusive.  The boat floated when backed into the water at the boat ramp - it did not take on any significant water.  There are two open drain holes just above the waterline on either side of the transom.  They serve as deck drains for the self-bailing desk.  They do not lead to the engine compartment but do not have any one-way type of check plate to prevent back-flow, so water could move freely in and out of the drain holes.  If the transom was lower in the water, it is possible that the boat could flood through the two drain holes.  In the engine compartment, one of the heat exchanger hoses was deteriorated at the connection point but could not be tested under pressure since the engine wasn't operable.  If that hose was leaking it could have contributed to the boat being heavier in the stern.   

The investigation determined the following possible cause of the boat flooding:  With six people on board plus full tank of gas (located near stern ) the boat would ride lower in the water.  In combination with possible leaking hose, the swells of 1-2 feet and some light wind, the drain holes could have been underwater for extended periods allowing water to flow into the engine compartment, causing the boat to get progressively heavier.

At the time of this report, the owner/operator's insurance company had not examined the boat to determine the extent of damages and cost to repair.  It is estimated that damages to the boat and gear is a minimum of $2,000.

Everett                       