Retired from newspapers and television, currently sailing Thelonious II, a 1984 Ericson 381.
The 27-year-old deck hatches didn't leak, sealed well, and the hardware was in good shape. The only problem was that the acrylic lenses looked like they had been in an auto accident--shot through with deep crazing resembling shattered safety glass. It turns out that the hatch acrylic is a standard plastics-house inventory item, with a choice of five or six shades of bronze or gray. Cutting and drilling is not a big deal for any local shop, and in my case Santa Monica Plastics did each hatch lens for about $80. All that remained was removal and installation. The Web page of Select Plastics offers suggested sealants--I used Dow 795 at the recommendation of Maine Sail, along with gray Butyl tape also purchased from Maine Sail's Compass Marine. I wish I could have visited his showroom, which I am told rivals LL Bean, with valet parking and a free croissant as you enter. Alas, life is butyl and short.
Here is a video on lens replacement.