Dave R - You make some good points. But what makes me believe in speed limits is reports from other lakes that have enacted them.
You bring up Lake George. Lt Sneider runs the Marine Patrol there and thinks speed limits have helped their lake. Here is a link to a citizen article on Lake George.
http://www.citizen.com/apps/pbcs.dll...073/-1/CITIZEN
I know Winnipesaukee is not Lake George, but if it can help there, it can help here. At least that is the way I see it.