Join Date: Sep 2008
Location: Victoria B.C. Canada
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Use acrylic (plexiglass). Lasts the longest, uv less of an issue, and probably less expensive. All major builders use acrylic. Lexan is not apparently available in less than sheet size with uv protection, without which it crazes within a few years.
My neighbor on a Spencer 35 has smoked plexi and it still looks new. Ports are original (1966).
Ideally the installation will not require holes in the acrylic, but if it does make sure to overdrill to allow for expansion. Sealant used is important - this is the only time I would use silicone on a boat as acrylics aren't compatible with many other sealants. Dow 795 structural adhesive is probably the best choice - better than silicone from Home Depot.