German, 8 pages, 4 figures
Keywords: Motorboat, waves, acceleration, injury, biomechanics

During a rough driving manoeuvre of a powerful motor boat on a lake a female passenger was allegedly thrown laterally against the driver’s seat . The injuries documented were a fracture of the sternum, cerebral concussion, cervical spine distortion and thorax contusion. No pre-existing degenerative changes in the cervical spine were reported (age 30 – 40 years). Since it was not clear at first sight why an object in a boat could be projected to the side an experimental reconstruction with the boat involved in the accident was performed.
It was found that during any driving manoeuvre – up to the tested 70 km/h – no lateral acceleration was measured if an even surface of the water was present. If, however, specific waves of 10 cm and higher were present a considerable lateral deceleration of the boat was registered during an oblique cutting of the waves. The dummy was projected against the drivers seat. The specific waves were caused by the boat itself while driving an 8-turn; any otherwise generated waves, of course, would have the same effect (wind, other boats).
Therefore, the injuries were accordable with the lateral fall caused by such a 8-turn manoeuvre.