Ridetheducksofseattle is reader-supported. When you buy through our links, we may earn an affiliate commission. Learn more

How to Set Up Boat Trailer Bunks – Super Easy Steps to Follow

Written by Anthony Roberts / Fact checked by Jonathan Larson

how to set up boat trailer bunks

Learning how to set up boat trailer bunks is one of the most important things for boat owners. After all, the bunk is what supports the boat’s hull when it’s sitting on the trailer. If you’re having trouble aligning the boat on the bunks or trailer rollers, this tutorial is for you.


Tools You May Need


  • Torque wrench
  • Adjustable wrench
  • Screwdriver

Steps to Set Up the Boat Trailer Bunks


By adjusting the trailer bunks, you’ll have a worry-free journey while towing your boat. The trailer bunks are going to sit on your trailer better, offering you and your loved ones a smoother ride. It also aids in launching and retrieving faster if you’re using keel rollers.

Plus, the properly-positioned bunks can also help in distributing the weight of your boat, providing an overall safer setup.

Step 1: Check the keel on your boat

See if the keel of the boat properly rests on the rollers, which may be attached to the trailer.

The keel takes about 70% of the boat’s weight. It is why you need to focus on the boat’s keel, and make sure that it is fully-supported.

Check if your boat is resting on the keel rollers well. If you noticed that it isn’t, you should bring an adjustable wrench. Loosen the brackets of the boat trailer roller, and then move the keel roller to ensure that it is resting properly on the keel of the boat. Begin at your trailer’s front portion going towards the rear.

Pro tip: Remove the boat before adjusting the rollers if you can’t get under the boat that is on the trailer. Take down notes of the space available and the measurement needed to raise the brackets.

Generally, the rollers located at the trailer’s front should be higher than the rollers at the back, following the keel’s shape and allowing for a quicker launch when at the ramp of the boat.

Step 2: Adjust boat trailer bunks

If you’re happy with the keel of the boat resting on the keel rollers properly, adjust the bunk brackets along with the hardware. With the boat resting on the rollers, adjust the trailer bunks but without removing the boat from the trailer.

Generally, the bunks rest about 1/3 up from the hull’s bottom. However, this may also vary from one manufacturer to another.

Start with the boat trailer’s front part by loosening the adjustable bunk brackets so that they can be raised freely. When the boat’s front portion is resting on the bunk guide, you can repeat the same process with the bunk bracket’s rear portion.

When you’ve finished the first side of the boat, you can do the same with the boat’s other side.

If the installation/adjustment has been done correctly, the boat should be resting firmly on the trailer bunks and keel rollers. Repeat the process from the start if the boat’s still not properly sitting. Inspect to see what part of the trailer isn’t sitting properly with the boat.

If needed, adjust the brackets to ensure that all the parts of the boat trailer are correctly resting with the boat.

Step 3: Repeat the same process.

Every time you’re launching and retrieving your boat, you must check the boat trailer bunk position, as the brackets might have shifted due to constant use. Adjust when needed.

Here is a useful video that you can also check out: Bunk Board Guide-on Installation


Remember, if the boat is positioned correctly with most of the boat’s weight resting on the roller, adjust the bunks while your boat is on the trailer for a smooth and steady ride.

The boat trailer setup might sound complicated for first time boat owners, but with a little help here and there, they can get by and learn how to set up boat trailer bunks. Follow the steps above and soon you will learn how to adjust the bunk system.

Hope you enjoyed and learned something from this tutorial. Have a safe and smooth ride. Besides, you also can refer more to wood for boat trailer bunks if you have demand. Finally, please spread the word and share this post on social media today if you like it!

5/5 - (3 votes)