The letter I in the number on the sail designates Lake Geneva sailboats that participate in the Inland Lakes Yachting Association races.  Above, a class E scow, one of the fastest and most elegant of sailing crafts.

I took sailing lessons at the Geneva Lake Sailing School, in association with the LGYC. As a young teen, I loved sailing, though I was torn first, by my love of horses and my wish to spend more time in the saddle than on the water. Then, once I started outgrowing the horsey phase, I was more interested in the guys who sailed than perfecting my techniques as a skipper.

Above is an M-16 scow, a class of boats built by the Melges Boat Works in Zenda, WI, a little town just south of Lake Geneva.  Buddy Melges is a world-renowned sailor and winner of all sorts of honors including an Olympic Gld and the America's Cup.

This is also on Lake Geneva, but I am not sure of the class of boat; it looks like something added long after I was no longer around.