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How to Lift Your Pontoon Boat off the Trailer Bunks



This is a proven method for lifting your boat off the trailer bunks for temporarily working on your pontoons. Cleaning, restoring and protecting your pontoons when your boat is still on the trailer is difficult. You can’t get to the bottom of the pontoons so they stay dirty and covered in marine growth plus the cleaners are likely to damage the carpeting and wood on the bunks and can damage the paint on the trailer. Following is a safe and easy way to lift your boat off the bunks by about 6 to 8 inches so you can protect your trailer with plastic and get to the bottom of the pontoons. If the boat were ever to slip off the blocks, it only has a few inches to fall back onto the trailer so there is no damage. Still, it’s important to work safely.

  • NOTE: This is general procedural guide. You may have to modify the procedure to suit your boat. For example: You may have to move your boat back to expose the back of the pontoons. If your boat is very heavy or extra-large, you may have to support the front across two or three cross members. If the trailer presents obstructions, you may have support the front of the pontoons on a beam supported by separate columns of blocks beside each pontoon.

lift pontoon off trailer - step 1

Using the right products to clean, brighten, protect and anti-foul your pontoons makes for quick, easy work and guaranteed results.

  • The easy way to remove algae from your pontoons is to spray them with Algex and then pressure wash them. Algex breaks the bond between the algae and aluminum for easy and complete removal.
  • To remove dark stains and brighten the pontoons, spray them with Marine Grade Alumabrite CBX and rinse until clean and silver. Use only marine grade cleaners made especially for boats. Industrial cleaners will etch the surface, turn them white and streaky.
  • To remove white etching, streaks and impossible stains, buff them out with Alumabuff, using a Linear Buffer. Alumabuff is proven to restore your pontoons in as little as 60 minutes per pontoon.
  • To protect your pontoons against staining and streaking in the future, protect them with Alumetron. It’s easy to apply and has a 5 Year Warranty. Be sure to wash your pontoons with Boat Clean Plus first for guaranteed results.
  • To protect your pontoons against marine fouling, apply VS721 Fouling Release coating below the water line. Most marine growth just wipes off with a sponge.

1. Hydraulic Bottle Jack of a capacity that meets or exceeds the weight of your boat.
2. 9 to 12 cinder blocks or wooden blocks 8″ x 8″ x 16″
3. 2” x 8” planks cut to 16” length pieces. You will need a minimum 3 pieces, but more may be required.
4. Wooden shims as required

CAUTION: This is a safe procedure when done correctly and with care. If
you do not feel confident in your abilities or equipment to handle heavy
weights, do not lift your boat in this way, get professional help.

These illustrations are not to scale.

pontoon on trailer picture drawing - aurora marine

1. Place the boat and trailer on a firm, level surface.

pontoon on trailer - lower front

2. Lower the tongue of the trailer to the ground to elevate the transom.. You may need a friend to help keep the tongue down.

pontoon on trailer - support transom with cinder blocks

3. Block the transom using cinder or wooden blocks. Make sure that there is a 2”x8”x16″ wooden plank between the pontoons and the blocks to prevent damage to the boat. If the blocks and wood do not fit between the ground and the boat, you may have to use additional pieces of 2”x8”x16″ wooden plank to compensate for the difference.

pontoon on trailer - lifting front with bottle jack

4. Place a hydraulic bottle jack under the tongue of the trailer and raise the front of the trailer. When the jack extends as high as possible, you may have to place blocks and wooden plates under the front cross member to support the boat. Then lower the jack and use wooden plates under the jack to give you additional height. Continue jacking up the trailer. This procedure may have to be repeated several times to gain the necessary height.

pontoon on trailer - support front of boat at forward frame cross member

5. Continue raising the front of the trailer until the boat is level or slightly bow high. Place blocks with a 2”x8”x16″ wooden plank on top, under the front cross member to support the boat.. Start lowering the jack until the weight of the boat is supported on the three columns of blocks and plates. Make sure that the boat is well supported on each column and is stable.

pontoon on trailer - supported with cinder blocks

proper use of cinder blocks - do not use cracked blocks

6. Lower the bottle jack. Extend the trailer jack to support the tongue and remove the bottle jack. The boat should be well supported and stable on all three columns and the bunks of the trailer should be about 6 to 8 inches lower than the bottom of the boat. This will give you clearance to clean and polish the areas normally supported by the bunks.

7. Do not remove the trailer. It will act as a safety device to catch the boat in the event that it slips off the blocks or if one of the blocks breaks or the ground becomes infirm and the blocks sink.

8. Do not proceed to work on the boat until it is well supported and stable.

9. To reseat the boat on the trailer, reverse the above procedure.


Raising your boat off the bunks or rollers allows you to gain access to the complete bottom so that you can remove growth with Algex, clean and brighten the bottom with Boat Scrub or Alumabrite CBX and to protect it against marine growth and Zebra mussels with VS721.

Its important to clean and protect the entire bottom. Working around the bunks and rollers will make any marine growth worse and will affect the performance of your boat. Leaving parts of your boat bottom unprotected can compromise the integrity of your boat.

This procedure is proven safe for boats up to 40 ft. providing that you follow the instructions and make sure that the ground is firm and level, that your trailer and equipment is sound and the blocks and wooden planks and shims are in good conditions. You may have to modify this procedure slightly or adjust your boat on the trailer depending on the style of your boat, for example pontoon, catamaran or monohull. This procedure is NOT recommended for sailboats with a fixed keel.


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