I asked a while ago for advice on adding keel guides to help get my CP16 centered. I stole your best ideas and put them in a mixer to come up with this: I bought 6 bunk board brackets and a pair of 4' carpeted 2x4's online. I bolted the carpeted boards to 5' x 6" sections of 1/2" ply then bolted those to the bunk board brackets (actually only used 4) I bolted the units to the trailer just outside the range of the keel rollers. Aft, the carpeted 2x4's do stick out a bit to "catch" the keel. It's all pretty sturdy buy the 1/2" ply offers just a hair of give. I used hot dipped galvanized bolts and lags and did have to drill a 5/16th hole in the trailer cross members for each bunk board support. That task got much easier as learned to start with a smaller bit first, well lubricated in teflon spray, then moved to the 5/16th. Anyhow, Have lots of pics if anyone likes it enough to want to build it. Enjoy: