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Boat Propeller Strike: How to Avoid Accidents

June 30, 2022

Propellers play a vital role in propulsion for many types of boats, but they can be extremely dangerous for people who get too close to them in the water. They can easily cause severe injuries and even prove fatal, so it’s important to take steps to minimize the risks.

Find out how boat propeller accidents occur and how they can be prevented in this article from the experts at Drive a Boat Canada.

What is a boat propeller strike?

A boat propeller strike is a type of accident where spinning propeller blades hit a human in the water. Propellers generally spin at a rate of 1,200 to 3,200 RPM, meaning that anyone who comes into contact with the blades may be hit as many as 160 times per second.

Propellers present a serious danger for anyone in the water nearby, including swimmers, divers, water-skiers and people who fall overboard. Spinning propellers pull water down and in towards the centre of the boat, meaning that anyone too close to the stern may get caught in the hydrodynamic flow and pulled into the path of the blades.

One of the worst-case scenarios, called the “circle of death”, occurs when the boat operator falls overboard and loses steering control. In such cases, the rotation of the propellers may cause the boat to turn in a circle, trapping and/or running over its operator in the water.

How can propeller strike accidents be prevented?

Fortunately, there are many steps that can be taken to prevent boat propeller accidents:

  • Never turn on the engine while people are getting on or off the boat.
  • Make sure everyone on board is seated before turning on the engine.
  • Walk around the boat and check the water on all sides before starting the engine.
  • Don’t let passengers sit or stand in precarious locations such as the transom, gunwales, bow and swim platform.
  • Keep well away from people in the water, other boats towing water-skiers, and diving flags and buoys that mark swimming zones.
  • Keep a sharp lookout at all times, and designate a passenger to watch the area around the propeller to make sure no one gets too close.
  • Ensure that everyone on board is wearing a personal flotation device at all times in case they fall overboard. In addition to keeping the wearer afloat in emergency situations, PFDs also provide extra visibility!
  • Take a boat license course to learn more about how to keep yourself and others safe on the water.

Devices that help prevent propeller strikes

In addition to the safety measures listed above, there are several types of devices that can be used to help prevent propeller strikes:

  • Propeller guards partially or completely encase the propeller in such a way that water can still get through, but human body parts are blocked from the blades.
  • Electronic sensors can be attached to everyone on board to automatically shut the engine off if someone falls overboard.
  • A lanyard kill switch attaches to the boat operator so that if they move too far from the helm, the line pulls free and automatically shuts off the engine.
  • Ladder interlocks sound an alarm or cause the engine to automatically shut down when someone is using the boat’s ladder.
  • A no feedback steering system prevents the “circle of death” scenario by counteracting prop torque and locking the steering onto the track set by the operator so that the boat never starts to circle by itself.

Boat safely with Drive a Boat Canada!

The best way to stay safe while boating is to be aware of the dangers involved and actively take steps to reduce risk. That’s why Canadian law requires prospective operators to take a safety course and pass a boating exam online or in person before getting out on the water. Register today to obtain your boating license and find out everything you need to know about boating safety!