BOATsmart! USA Knowledge Base

Module 06 - Other Water Activities Emergency Preparation

Propeller Strike Awareness

Your boat’s propeller (also known as the ‘prop’) is a dangerous piece of equipment for swimmers and towed sport participants. Props are underwater objects that spin quickly and force your boat through the water. Contact with a propeller can cause devastating injuries or in some cases, even death.

Propeller Safety Equipment

If used properly, propeller safety equipment—such as a ‘propeller guard’, which cages the propeller—can help to prevent propeller strike injuries from taking place.

Additional propeller safety equipment may include:

Ladder interlocks: These are devices that sound an alarm or automatically shut down the engine when passengers use the boat’s swim ladder.
Wrist lanyard or engine kill switch: The operator wears this device and if they fall overboard, it will automatically shut the engine off, preventing the ‘circle of death’ scenario from occurring.
Electronic sensors: Your passengers wear these sensors and if they detect that a person has entered the water, the sensors will electronically shut the engine off.

How to Prevent a Propeller Strike Accident:

Never operate your boat near ANYONE in the water—including swimmers, divers, skiers, etc.
Always shut down your engine while passengers are entering or exiting the boat.
Make sure your passengers are seated before getting underway.
Ask a spotter to help you watch for people in the water.

Note: Each year, propeller strike incidents represent 4% of all boating-related fatalities in the U.S. Remind your passengers that even when the engine is off, the prop is sharp and can be a dangerous underwater object for swimmers to come into contact with.