Singer Sean Kingston hit a bridge in Miami while operating a Jet Ski personal watercraft, sending him and his passenger to the hospital. The Jamaica-born hip-hop star is in stable condition, but his accident is raising questions about the safety of crafts like the Jet Ski.

The Kingston incident is being investigated, but Jorge Pino, spokesman for the Florida Fish and Wildlife Commission, the lead investigative agency of the accident, says the cause of the crash, like most PWC (personal watercraft) accidents, is most likely recklessness.

A National Transportation Safety Board (NTSB) study reports that the primary causes of PWC accidents are inattention, inexperience, and inappropriate speed. Carrying a passenger may contribute to inattention. One third of PWC operators have limited experience on the craft, with 84 percent reporting that they had no training on the craft.

Because Jet Skis do not have a propeller or other steerable appendage in the water, throttling down reduces the operator's control of the craft. Becoming airborne by jumping a wave or wake eliminates the operator's control. Inexperienced drivers will not know this.

Inappropriate speed is subjective, but operators must consider that while traveling 40 miles per hour, which is not the maximum speed for many PWC, the craft travels about 20 yards per second.

Nearly 5 percent of the injuries on personal watercraft are fatal. Half of PWC accident injuries are to the lower extremities, and most of these involve broken bones. Vessel collisions are the leading cause of injuries, although PWCs also collide with skiers and swimmers. Many injuries are caused by the operator's foot getting caught as they are thrown from the craft. Others suffer facial injuries when their face hits a part of the craft after a sudden jolt--after being airborne or hitting a wave, for instance.

The Personal Watercraft Industry Association suggests the following to increase PWC safety:

- To avoid collisions, scan constantly for people, objects, and other crafts.

- Operate the craft defensively, by not approaching or following other watercraft too closely, by not going too close to others to splash them, by avoiding sharp turns that could make you lose control of the craft and make it difficult for others to understand where you are going, and by avoiding areas with submerged objects or shallow water.

- Take early action to avoid collisions, and remember that watercraft do not have brakes.

- Do not release the throttle when trying to avoid something. You need the throttle to steer on a PWC.

And, of course, always wear a personal flotation device and do not use drugs or alcohol before operating a personal watercraft.