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How to Install a Killswitch on a Boat in 4 Detailed Steps

Fact checked by William Hart

Install a killswitch on a boat

Even though kill switches may appear to be the same at first glance, there is actually more than one type of engine kill switch. For that reason, you need to know which kind of kill switch you have to set up the right way; moreover, new boating laws have made it mandatory for watercraft to have a safety-stop lanyard on board.

Today’s article includes a thorough guide on how to install a killswitch on a boat properly and safely. Stay tuned!

Table of Contents

Step-by-step to Install a Killswitch on a Boat

What to Prepare


  • Fell Marine MOB+ Basepack
  • Drill
  • Wire strippers
  • Hole saw (2-⅛ inch diameter)
  • Crimping tool

The following installation guide includes steps to fit a wireless kill switch into your vessel.

Step 1: Install the XHub


First, you’d need to locate a spot near the flywheel for the kill switch installation. Then, drill a hole of 2-1/16” (52mm). The xHub antenna is 6-½” long, so make sure you have sufficient room for that.

Remove the xHub nut by turning it, then secure the antenna to the back of the unit. Place the xHub into the prepared hole, with the antenna facing inside.

Now, the gasket should lie in between the xHub and the surface surrounding the hole. Additionally, set the battery indicator direction at 12 o’clock and the FELL printing in the opposite direction.

Once everything is set nicely, tighten the xHub by hand while inserting the five-pin connector into the back of the unit.

Step 2: Connect to Power


Before you set up the wires to wire a kill switch, disconnect the power source with a wrench for safety reasons.

The pigtail includes 5 color-coded wires: orange, blue, gray, black, and red. The red (positive) wire should be linked to a 12V DC power supply, whereas the black (negative) wire should be linked to the onboard ground connection.

When connecting the red wire to the power supply, opt for a fuse (1 to 3 amp) and a fuse block or a marine in-line fuse holder. If the ground wires aren’t sufficient, use 20 AWG or thicker wires.

Step 3: Attach Signal Wires


Two of the three remaining wires are meant to be connected to the kill switch wires of your vessel. Double-check with the manufacturer’s website for the wiring principle of your boat.

If you happen to have a Mercury kill switch, remember the xHub gray wire goes with the kill switch black/yellow wire, and the xHub orange wire goes with the kill switch black.

Step 4: Run a Test


After you have set up everything, it’s time to check if the system is working properly.

When you’re at a dock, start the engine, then pull the lanyard to see if it works. After that, reconnect the lanyard and restart the motor.

Exceed the working distance by walking away from the vessel to see if the engine stops or submerge the xFob remote in the water (4 inches). The working distance may differ depending on the environment around your vessel; the minimum length is 15ft (5m), and it can exceed up to 30ft (10m).

It should take less than 1 second for the system to function.


How Does A Boat Kill Switch Work?

A kill switch will immediately cut off the engine when the skipper falls overboard.

It links the captain and engine directly via a tether, so when the captain moves away from the specified distance, the tether is pulled and acts as a switch to turn off the engine.

Nonetheless, there are also wireless models like the one mentioned in this article that work just as effectively.

Is It Mandatory To Install A Kill Switch To Your Boat?

From April 1, 2021, a federal law was released to enforce the obligation to install a kill switch for vessels under 26’ in length. If you fail to have this boat safety device on board, expect to face a fine of up to $100.


By now, you should know how to install a killswitch on a boat! The process of fitting a kill switch to your vessel can be a bit challenging at first, but as long as you follow our guide attentively, things will turn out nicely in the end.

Installing a kill switch isn’t just a good idea, it has become part of the law since 2021. Even though falling off a boat may not be a common thing, you never know what’s going to happen when you’re out and about on the water. Better safe than sorry!

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