A few years ago I was teaching a new diver class at the old Laconia Athletic & Swim Club. Another patron of the club engaged me in a conversation. Turns out he was a participant in the laser testing that took place at the Diamond Island site many years ago. He told me that the underwater steel frame was used to allow the US Navy to perform some of their laser testing during the daytime. In the NH Chronicle story you will notice several large bungee cords laying on the lake bottom around the steel frame. According to the fellow I spoke with, these bungee cords were used to hold plywood structures in place on the surface of the lake. The tops of the plywood structures were painted black to prevent the sun from penetrating below causing darkness underneath to allow the laser testing to occur. The front of the steel frame is in about 21 feet of water while the back of it is in about 32 feet of water. There is usually a few small mouth bass around the steel frame.
When Dive Winnipesaukee takes dive charters to this area, we do a short tour of the steel frame and then set a 60 degree compass course from the right front corner of it. This course will take you to a rock jetty that comes off Diamond Island. The jetty used to support a dock that was used more than 150 years ago by old steamers, like The Lady of the Lake, when they brought passengers to the hotel that used to be on Diamond Island. See this link:
http://www.lwhs.us/gilford/diamondisland.htm. For Part 2, see this link:
http://www.lwhs.us/gilford/diamondisland2.htm
The jetty is now home to a lot of fishing line & tackle trapped by the rocks as unsuspecting deep water fishermen cut close to Diamond Island from The Broads side of the lake. The lake bottom comes up so quickly that it snags the fishing lines and snaps them. I also found 2 anchors out there this summer.