First had them in Newport @ the Ark for the America's Cup.
Have had one or two since then....
The best place i've had them is The
Dinghy club (pink bldg) in Bermuda is a great spot for the cocktail. Mostly locals. The Willy T on Norman Island, BVI, has great one's also, so I've read.... Have made "partly cloudy's" for those who want a toned down version of the dark.
There was an article in the WSJ about the cocktail. Pretty funny. They were most emphatic about building them. The only thing that goes into a dark is Gosling's, Ginger beer and "if you have to put a lime in it, please don't squeeze it." Some folks add a dash of bitters.
Cheers