What prevents the ignition of gasoline fumes when the inboard engine backfires on a boat?

What came first a boat or a wheel? What is White lettering on road? What age do children have to wear a USCG approved life jacket in a boat less then 26 feet in the state of La? Where can one rent a center console fishing boat? Do you need a passport to enter the Bahamas from a cruise ship leaving a US port? Is the recommended method for storing your Personal Flotation Devices (PFD) on board a boat? How long does it take to sail a 42' Catalina sailboat from San Diego to Santa Catalina iIsland? When a vessel is entering or leaving a port record of engine speeds is kept in the? How much does a Steamboat ticket cost in the year of 1850? When operating south of Interstate Highway10 what distance should a vessel operator maintain when jumping another vessels wake or following a water skier? Do the water pump bolts go through the water jacket on a 1979 Chevy 350 when removing bolts water pours out of one of the bolts hole.? What did they eat on sailing ships? You are caught in a storm in your boat and your engine stops. What should you do? Parts of a drilling rig? What is the oil mixture on 1989 WaveRunner? What does cruise only mean? Is there a boat from Majorca to Barcelona? What does helm mean like steady your helm? What to do if you are involved in a collision and your pleasure craft is flooding.? What is sheltered side of ship called?