It's interesting to see that petrol inboard engines are essentially banned on commercial vessels with the new rules coming into effect soon, no doubt because of the risk of fire and explosion.

If you want statistics...
Australian Boating Incidents 2005

Particular attention should be paid to capsizes and falling overboard...they accounted for 50% of fatalities.

Particular attention should also be paid to recreational boat use..they accounted for 79% of fatalities.