Propeller Strikes: Cause, Prevention, Treatment

Propeller strikes cause serious injury or death every year. While it's true PWCs don't have propellers, many PWC users have the opportunity to operate outboards, inboards or inboard/outboards. It's important to understand the dangers propellers present.

Situations where propeller strikes may occur

A typical Powerboat propeller is turning at about 470 RPM when the engine is at idle. The propeller usually has three blades which results in about 24 strikes of a blade per second. The propeller on a boat at speed can be spinning at 3-4 times idle speed. This can do a lot of damage and injury before the engine can be shut off. In 2006 the U.S. Coast Guard recorded 150 persons involved propeller strike accidents, 25 of them fatal. If not fatal the injury as a result of a propeller strike is often disabling.

Here are some common ways a person may become a victim of a propeller strike:

1. Operator of a small boat equipped with an outboard with either tiller or cable steering falls overboard and is hit by the circling boat. Most outboards with either tiller, or cable and pulley steering will tend to circle if the tiller or steering wheel is not controlled and it's not equipped with an ignition shut-off switch and lanyard.

2. Water skier is in the water at the transom putting on the skis. Engine is running. The engine is inadvertently put in gear. The skier's leg is hit by the propeller.

3. Water skier is in the water and awaiting pick-up. The boat idles straight towards them. The operator is inexperienced and doesn't know which way to turn. The boat goes over the skier that results in a propeller strike.

4. Water skier is in the water and awaiting pick-up. The boat comes around to pick them up and overshoots the skier. The boat operator puts the boat in reverse and backs towards the skier hitting the skier's legs.

5. A boat is traveling across a lake with two children sitting on the bow, not in seats. The boat hits a wake or the operator turns to avoid a log. The children slide over the bow and are struck by the propeller. In 2006 the U.S. Coast Guard recorded 41 children involved in propeller strike accidents.

6. Swimmer(s) are hanging on the swim step talking or getting ready to get in the boat. The operator looks around, doesn't see the swimmers at the transom and starts the engine in gear. The swimmers are hit by the propeller.

7. A person is diving into the water off of a dock or float. The boat comes by close to the dock while the person is surfacing, and the person is hit by the propeller.

8. A S.C.U.B.A. diver comes to the surface, the boat operator doesn't see the diver flag or there isn't one and the diver is hit.

9. The operator is approaching a dock in an area where there are swimmers. A swimmer surfaces after swimming under water. The boat hits the swimmer.

As you can see most if not all of these propeller strike incidents are caused by operator error and inattention. Nationally the leading cause of propeller strike accidents is operator error. Remember on the water the operator is responsible for the actions of the PWC or boat.

Prevention of Propeller Strike Accidents

Simple things you can do to prevent propeller strikes:

1. Always use and attach the ignition shut off switch if your boat is so equipped. Attach the lanyard to your PFD or cloths or around your wrist securely.

2. Everyone onboard the boat should be made aware of the dangers associated with the propeller and how to prevent them.

3. When approaching anyone in the water do so at a dead-slow speed. Shut off the engine and let the boat drift towards them. Throw them a line or extend them a pole and pull them to the boat or swim step if necessary.

4. When the person in the water has gotten into the boat, check to make sure nothing (another person, floats, skis, tow line, etc.) is in the water near the transom.

5. The operator in a loud voice should ask "CLEAR?" before starting the engine. If the operator asks "CLEAR?" and an observer or person checking the water at the transom sees anything or anyone in close proximity to the propeller or transom, then the response to the operator is a loud, clear "NO".

6. If a skier is getting into the water to go skiing or a swimmer is in the water to swim to shore or a float, be sure they get well away from the boat before starting the engine.

7. Remain outside and away from any swimming or diving or S.C.U.B.A. activity. If you need to go to a dock near a swim area, paddle your boat from a safe distance with the engine off and the outboard or I/O tilted.

8. Always be aware of your surroundings, keep your head and eyes moving. Don't develop tunnel vision.

If you are in a small boat with an outboard with an ignition shut-off device and lanyard, use it. If your boat is older or not equipped with the shut-off device ask your marine dealer or mechanic about installing one. This item alone will stop many needless prop strike accidents. This add-on switch with lanyard is moderately priced. It can be found on line or thru your local marine supplier or repair facility. A wireless model is also available.

If your boat is equipped with a neutral safety switch that prevents starting the engine in gear be sure it works properly.

Be familiar with local laws regarding the distance a powerboat or PWC must remain from swimmers and other water activity and follow them.

Many manufacturers are selling various styles of propeller guards. These guards fit around the propeller and deflect objects to the side and away from the spinning blades. They are made for various applications. There are also sensors that will not allow the engine to start if the boarding ladder is down. Contact your marine dealer or repair facility about these safety items.

Many groups are concerned with the prevention of propeller strikes. These can be found on line.

CAUTION: Some propellers will continue to spin for a short time after the engine is shut off. This is caused by the weight of the propeller and the movement of the boat through the water.

Most PWCs are equipped with a lanyard shut off device. You are required to attach it to your person (wrist), clothes, or PFD when underway. No one should be allowed to play around or be in the water near the PWC with the engine running. Most jet areas are secure from a person touching the spinning impeller however fingers, toes, hair or clothing may still get stuck in the intake grate or areas around the exhaust and steering unit. The water exhausting out the jet unit has force that may cause injuries.

Treatment of Propeller Strikes

1. Perform First Aid to control the bleeding if trained. This can be done by wrapping a wet towel tightly around the cut.

2. Call for medical aid if a Marine VHF or cell phone is available.

3. Have the boat operator proceed as fast as possible to a populated shore where medical aid can be summoned or to a meeting spot where aid is waiting.

4. Keep the injured party calm and lying down.

5. Advise medical aid of what the injuries are.

6. Do not remove the wet wrap from the cut.