The Gulfstream 'offset' usually is current going north at about at least 2+ knots in the center axis of the stream, can be as much as 3-4 knots depending on the weather in the Yucatan Channel between Mexico and Cuba. For a boat that can continually maintain approx 6 knots forward that means during 'normal' flow in the stream and a 'good' weather window that you will typically have to head about 20 degrees more southerly to land at your desired port. With a small waterline length boat that can translate to a ~30 degree offset due to the current, and 1/2 the resultant speed to your desired port .... resulting in a passage TWICE as long as planned.
Also too the Northwest Channel between Grand Bahama and the Berry Islands/Andros will/can have a westward flowing current of 1-2 knots - directly on the nose when going easterly.
For a boat such as yours with an extremely short waterline length, Id suggest:
To Grand Bahama/Abacos - Leave from Ft. Lauderdale and head for West End, then sail the Little Bahama Banks eastwards to the Abacos .... etc.
To Nassau - Leave Miami and head for Bimini, the sail the Grand Bahama Banks towards Nassau, etc.
What you DONT want to do is attempt to sail a straight-line GPS waypoint course across the Gulfstream. Rather sail/motor an S-shaped course so that you are going SE right off the FL coast, ACROSS the Gulfstream at the point of its highest velocity and then more northerly closer to your destination - do most of your 'southing' early in the passage. In this way, if the Gulfstream flow rate is higher than normal which causes you to 'overshoot/miss' your destination .... you wont wind up in IRELAND.
My suggestion for your short waterline boat also includes to WAIT for a good weather window of SEVERAL DAYS of 'benign' winds and waves, as it sometimes take DAYS for the sometimes intense easterly swells to settle down during the Christmas Tradewind times .... then simply MOTOR ACROSS to either West End or Bimini.
Late December and January .... sometimes from mid-December all the way into mid-February is the time of the "CHRISTMAS TRADE WINDS" which are minimum 20-25++ NORTH-easterly winds, sometimes which blow 'constantly' for days or weeks at a time. In a small boat you DO NOT cross the GulfStream when the wind has ANY 'northerly component' as the seas can/will be 'tremendous to outright dangerous'. Even with good weather windows and predictions, when you leave your chosen inlet towards the Bahamas you keenly look at the far eastern horizon; and, if what you see along the eastern horizon looks like a 'parade of marching elephants on the horizon', immediately do a 180 and go back through the inlet and wait for better sea-state.
The Florida Straights can have LOTS of big ship traffic ... suggest an AIS receiver and a 'good' VHF radio to 'contact' these ships when necessary, as with a small boat with hindered speed capability you will/can be at a great disadvantage in 'getting out of their way' when they are at FULL speed; plus, many such crews do not speak 'english' and many times perhaps there is NO ONE on the bridge controlling the boat or they simply DO NOT answer.
For your weather window take NOAA forecasts 'with a grain of salt'. Instead 'listen in' to the professional weather routers on 4.045mHz (USB) SSB starting at 7:00 in the AM, starting DAYS before your anticipated departure. Plan to cross during a LONG (safer) benign weather window. Do NOT cross the Gulfstream at the WRONG weather time because 'you are on a schedule' ... as you can 'have your azz handed to you'.
Lastly, sailing across the Gulfstream in the Florida Straights is the same as 'deep open ocean' sailing and if youre not used to sailing the open ocean, I suggest you get some ample practice before making a crossing to the Bahamas. ;-)
;-)
