The trailer that I purchased had two carpeted bunks to support the hull of my flat bottom boat. I felt that they did not go far enough forward to give adequate support to the entire bottom, so I added a 4 by 4 stick of wood to the trailer that my keel would be able to rest upon.

There were existing holes at three of the cross members to fasting the wood to, but none up near the front of the trailer. I cut two short lengths of mild steel to serve as backing for a custom u-bolt.

I gave a trailer supply shop my dimensions for the u-bolts I needed, and they made them on site. The only problem was they weren't painted or galvanized, but I am about to remedy that.

I made notches on the wood to recess the u-bolts using first a router, and then a file. I also notched the wood by a half inch at each cross member to help lock it in place, and to provide the lowest profile and center of gravity for this trailer.

The wood gets painted for its own protection.

The last step was to staple on boating bunk carpet to the wood. Once the boat is on the trailer, I can raise or lower the two outboard bunks so that the hull is supported equally between the three.

I had earlier installed a tongue jack, and while it has a wheel and can be moved around on a solid hard surface, it was very difficult to move the boat and trailer on the grass in my back yard. I decided to make some detachable wheels for the trailer's tongue.

I started with a 4 by 4 inch block of wood 12-inches long. I routed out a slot lengthwise 5/8th-inch square to be able to recess the 5/8th-inch steel rod.

I capped the bottom of the 4 by 4 with a 2 by 4 the same length.

I cut the steel rod down to 27-inches in length, and then drilled a hole at each end to accept a cotter pin.

I inserted the rod into the wood block followed by two large washers. I then mounted two 16-inch wheelbarrow-type wheels to the rod, followed by two more large washers on each side. The cotter pins locked everything together.

I still needed a way to attach the wheel unit to the tongue, and it was still a bit lower than I wanted. I increased the height by adding a 2 by 8, and a 2 by 4 was added perpendicularly both for height and the means of attachment. I could have made something fancier here, but the easiest way to attach the thing was to simply tie it on. This system goes over any bump in my yard with ease, but only in a straight line. I use a 5-foot long 2 by 4 to lift and pry the tongue over to point in any direction I like. It is actually easier to do than it sounds. One person can now move the boat.