Bob Trapani, Jr. from the ALF sent me this link to a new article he's written on the VRB-25 lighthouse lens. As always is the case with his articles, there is a TON of information as well as some excellent photos he's taken of the workings of lighthouses. Bob is always a good read. And if you've never visited his Storm Heros website, do yourself a favor and follow the links at the top of this article. Guaranteed you'll learn a few things about the Coast Guard and lighthouses.
http://www.stormheroes.com/aton/vrb25_200904.htm