Procedure:

After some research and design, I came up with a basic bumper design that I could build from materials I had and some basic fasteners from a local store. I started with a roll of 1/2 inch thick closed-cell foam that I cut into two 2 by 1 foot rectangles. I then sewed the two pieces together using paracord. To protect the boat from rubbing directly against the black foam and potentially rubbing color off or tearing the foam I sewed a cover made from a few yards of fabric and a zipper. Once the foam was in the zippered cover I tested it at home by wrapping it around a pole with a nylon belt and dual-sided release clasp as a fastener. Once I determined that the belt could hold it around a pole I tested it a few times on the boat so see how well it performed at keeping the boat off the dock.

Findings:

The prototype performed spectacularly for what it is. It was dense enough to prevent the boat from squishing it flat against the pole but was easy to stow and use. it took up considerably less space than the bumpers and was far easier to attach to the poles. A few improvements that could be corrected in future designs:

• It should be made of a single piece of foam as water can get between the two rectangles and make it smell if not properly dried
• A lower density foam could be used so it’s lighter and potentially make it a bit thicker so it is softer for the boat to push against
• The belt and clasp should be sewed onto the cover or better yet pass through the foam to be more secure and easier yet to attach to the pole
• Closed-cell foam works well but isn’t too visually pleasing potentially a foam with a rubberized coating could be used in its place

Next steps:

For the next prototype, I plan to choose a different type of foam and will implement some of the design improvements noted above. In the meantime, the current prototype will continue to be used and tested and other potential improvements and flaws will be noted.

Photos:

Sewing the cover for the prototype:
Without the prototype fender (notice the lower fenders fail to keep the boat off the pole):
The prototype fender in use: