I’ve chosen to go with several thin strips of 16″ (0.8″ X 0.45″) teak for the outboard cap rail/rub rail. The Glen-L plans for Lo-Voltage call for mahogany over 1″ in various sizes.
Using smaller strips is more time consuming, but very easy to work with when you are doing the job alone. Best of all, it yields a stronger finished laminate beam if you use proper epoxy glue and clamps.
I found it’s very hard to stem and clamp into place a 16″ strip of wood before it cools. For example, in the photo below, the plans call for a single (1 1/4″ x 1″) strip where I am using 6 laminates producing relatively the same size rub rail.