Propeller is a device with blades that rotates to create pressure and makes the boat move forward.
While it is an essential part of the boat, it is also known to cause some injuries. However, most of these injuries can be avoided with a piece of equipment.
Wondering what piece of equipment on a boat is most important in preventing propeller strike injuries?
The ignition safety switch lanyard (also knows as kill switch lanyard) is the equipment on the boat to prevent injuries from propeller strike.

Can a boat propeller strike cause death?
Yes, the boat propellers can cause severe injury due to high speed and torque.
It can mangle the body of someone in the water or cause permanent damage and disfiguration. In the worst cases, rotating propellers can kill a person.
The propeller of a boat works below the surface of the water, rotating at top speed and creating an intense force.
It is usually not visible to the operators, passengers and swimmers.
The most common propeller strike events are crew-overboard or circle of death.
In case of a crew overboard event, you should stop the propeller from spinning by shifting to neutral and immediately turn towards the direction of person in water pushing the stern in opposite direction.
If the operator loses control of steering or goes overboard, the circle of death event can occur. The spinning propeller when control over steering is lost will apply throttle making the boat circle. This situation has the potential that the operator or passenger who is in the water will get hit by the propeller due to the circling action of the boat.
How does the ignition safety switch lanyard prevent propeller strike injuries?
The safety switch stays connected to your wrist or life jacket with the help of the lanyard. If you fall off the boat while operating it, the lanyard will pull the switch, thus cutting off the engine and propeller.
The ignition safety switches lanyard, or kill cord, doesn’t prevent a person from getting close to the rotating propeller. It prevents injury by stopping the engine and the propeller when a boater falls.
Also, this technique will not save a person who is already in the water or does not have a lanyard attached to him.
How to fit an ignition safety switch lanyard?
To install the ignition safety switch lanyard, you first need to fit a kill switch into the boat’s dashboard or engine.
In a small boat, this switch can be fitted to the outboard motor directly. In the case of a large boat, it has to be set on the console that has the other controls.
There are many types of kill switch lanyards, which are mostly made of coiled plastic wire or cord and look similar.
Attach one end of the wire to the kill switch and the other end has a clip i.e. attached to your life jacket.
Do lanyards are enough to prevent propeller strike accidents?
The answer is “NO”
The safety switch lanyards are one of the ways to prevent propellers strike accidents but they do not provide protection to people who are already in water.
In addition to installing an ignition safety switch lanyards, here are few other types of equipment that can provide protection against safety switch lanyard:
- Prop Guard
- Ringed Propeller
- Propulsion Alternatives
- Ladder Interlock
- Electronic Sensors
- Wireless Cut-Off Switches
How can propeller strike accidents be avoided?
Here are few others tips to keep in mind to prevent propeller strike accident:
- Switch off the engine when passengers get on the boat, leave it, or are vulnerable.
- Be careful while boating to prevent the passengers from falling into the water.
- Do not start your boat when the engine is in gear to prevent a fall.
- Ensure that passengers are seated properly in the dedicated space on the boat.
- Keep an eye on passengers, especially children, to ensure that they do not leave the boat or fall.
- Avoid congested areas like swimming and diving regions or anchorages by looking out for flags.
- Keep an eye out for unsuspecting swimmers and divers in the water.
- The leading factor contributing to fatal boating accidents in the US in 2019 is alcohol abuse. It has led to 23% of deaths caused by propeller strikes. Do not drink alcohol or indulge in recreational drugs before or during boating.
Taking your boater exam seriously to prevent propeller strike injuries
It’s essential to take your boater exam seriously, as it can eventually help you prevent propeller strike injuries and accidents.
Knowing the safety measures to avoid accidents is not just about clearing the exam. Rather, learn from them and apply them appropriately.
Clicking on the right answer is easy. It can be guesswork, or you can even cheat. But that’s not advisable – not just for moral reasons, but because preparing for the exam will give you the chance to become a responsible boater.
That’s the whole point of the exam anyway – to help you be cautious.
Final words on what piece of equipment on a boat is most important in preventing propeller strike injuries?
Propeller strike accidents are more common and dangerous than you can imagine, but they can be prevented.
Kill cords are cheap and simple equipment to prevent propller strike accident but it is recommended that you install other safety equipment as well.
It is also important to be a responsible boater for the safety of your passengers, swimmers or divers in the water.
Follow all the safety tips to enjoy a safe ride.