How to Stop a Boat From Swaying

Even slight winds can cause your boat to sway.

Towing a boat presents a number of problems for drivers. The weight of the boat increases the amount of time and distance needed to come to a stop. A trailer carrying a boat can also sway. This swaying can vary from minimal side-to-side motion that might dislodge unsecured items inside the boat to the trailer swaying back and forth across lanes. Extreme swaying can cause the boat to overturn inside the trailer. Drivers can prevent sway by purchasing proper trailering equipment, towing safely and driving proactively when towing a boat.

Instructions

1. Purchase a tandem-, or dual-axle trailer if hauling a boat over 17 feet in length. Unlike a single-axle trailer, tandem-axles provide two or more sets of wheels. The extra axle and wheels keep the trailer more likely to move in a straight line, which prevents swaying.

2. Use a trailer that places 15 percent of the weight of the trailer in the tongue, or part of the trailer that extends from the load to where the trailer attaches to the truck. A heavier tongue exerts more downward force on the tow hitch and moves the center of gravity of the weight towed closer to the vehicle, both of which prevent swaying.

3. Shift any items stowed in the boat to the front of the boat. Moving items into the fore of the boat will help increase the tongue weight and shift the center of gravity further toward the towing vehicle.

4. Decelerate slowly the moment the boat starts to sway when driving uphill or on flat surfaces. Avoid the urge to hit the brakes or speed up when the boat begins to sway. When driving on a flat surface or uphill, both of these responses will only increase the sway of the trailer carrying your boat.

5. Increase the speed of your vehicle slightly if the boat starts to sway when driving downhill. Apply the accelerator gently; an increase in the towing vehicle’s speed will give the trailer time to catch up to the car. As the trailer catches up to the car, it will straighten out its path and stop swaying.

6. Avoid sway by manually applying the trailer brakes before braking, where applicable. Some states, such as California, require trailers to feature a controller inside the towing vehicle -- this controller coordinates the braking of the vehicle with the trailer’s brakes. If your controller offers a manual button, press the button in to begin braking the trailer before you start braking the towing vehicle.

7. Apply the brakes early when approaching stop signs and stoplights. The weight of the boat in the trailer will resist braking and push the towing vehicle forward as it tries to stop. If a driver brakes too suddenly, the excess energy of the trailer and boat moving forward will also shift from side-to-side, causing sway.

8. Drive at speeds that are lower than the speed limit. The greater the speed of your vehicle, the more likely the boat and trailer will begin to sway.

9. Drive slower in high winds, especially if towing a boat with a minivan. Unlike a truck, the boxy shape of a minivan catches more wind moving sideways against the van and the trailer. The wind then pushes the minivan to the side; as the driver corrects the car’s path, the trailer starts to sway in tandem with the minivan’s side-to-side movement.

Tips & Warnings

• Let some of the air out of the trailer’s tires. A slight decrease in the air pressure of the tires can reduce sway.

• Avoid pulling more boat than your truck, sport utility vehicle or van can safely tow. Remember that any items stored in the boat add to the amount of weight towed.

References

• Walleye Tour Professional; Trailering shouldn’t be a drag: A Pro’s solution to trailering problems; John Campbell
• California Department of Motor Vehicles: Towing Your Trailer Safely
• Bob's How To: Dual axle utility trailer selection
• Hitching Up: Tongue Weight

Resources

• National Highway Traffic Safety Administration: Towing a Trailer: Being Equipped for Safety