The Storm Lake Iowa Laass v. Brunswick case has focused attention on outboard marine drives striking submerged objects and flying back up into the boat. In the Storm Lake accident, a ten year old boy, David Paul McFarlin was killed on May 31, 2010. A 175 HP Mercury outboard struck a submerged dredge pipe, flipped back up into the boat, and the boy was killed by its propeller.
First, a point of clarification. The U.S. Coast Guard does not recognize accidents in which people are on boats or otherwise not in the water when they are struck by propellers as propeller accidents, so this is “officially” not a propeller accident.
Marine drive manufacturers use relief valves and check valves in the trim systems of stern drives and larger outboards to cushion the blow and absorb the energy of striking submerged objects. The relief valves allow the cylinder rod to extend (drive to swing up as it dissipates energy), then the check valves allow the cylinder piston to settle back down to a “memory” piston. Mercury Marine is well known for conducting log strike tests which we discuss on our Laass v. Brunswick page, and supply an early video near the bottom of this page.
We often see U.S. Coast Guard Boating Accident Report Database (BARD) reports in which an outboard was torn from or broke off the transom. Some of these outboards sink, while others remain attached by cables, hoses, and/or fuel lines. In some portion of these instances, the outboard strikes a submerged object and actually flies up / flips up and lands in the boat. As a result, people in the boat can be struck by the outboard or cut by its still rotating propeller.
We decided to investigate BARD and some other sources to gain some greater understanding of these types of accidents and perhaps some insights into their frequency. Read More→