I installed frameless Acrylic portlights
about 1 year ago, and after reading the "sexy windows" thread, and related material, I choose 3M adhesive
tape, along with Dow 795 to adhere and seal the edges and couldn't be happier. I would not throughbolt. If I were crossing oceans I might reconsider, but mine are on there really strong. Any wave strong enough to knock them out would knock the boat over 1st.
now. I would thinks your way could still leak next to the bolts, as the windows expand and contract
It was easy to cut mine to shape with a router, and then shape the corners with a belt sander.
Here's a couple of pics.