Re: Miami to Bimini
I would go in November. The weather will be marginally better...but the water will be cold by then though.
A week is a perfect amount of time to poke over to Bimini. To be honest, there isn't TOO much to do over there, however the passages alone will take up two of your seven days of vacation. The challenge is that in the winter, you'll get cold fronts every 3-4 days. While these fronts usually create a weather window in advance of their arrival, when they do arrive, they can make the Gulfstream really snotty...if not downright dangerous. You may get pinned there beyond your vacation window.
Since you own your business, whats the harm in just leaving your return a bit open ended and coming back when the weather allows.