Crabbing to the Bahamas

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In any given cross section, the Gulf Stream moves the same amount of water per second as 5000 of the Niagara Falls (US & CAN). If you don’t account for this in crossing from Florida to the Bahamas, it can be a too interesting trip. Certainly, northerly wind against this massive current gets a lot of attention, but there are navigation and sail trim issues to consider.

The Port Everglades to West End route is 69.1 nm at 058°T. If the boat could put its bow on 058 and just go, good wind and swell direction would be relatively easy to describe. But during the trip for a boat sailing between 6-and 6.5 knots, the bow will be pointing as much as 45 degrees south of the heading for West End, and the apparent wind will move forward. Also, the motion of the current must be subtracted from the motion of the wind — 15 knot southerlies become 12 knots, this can also move the apparent wind forward. That nice easy reach can turn into a swell punching beat for 1/3 to 1/2 of the trip.

The graphic above shows our bow pointing 103 degrees to crab against the strongest flow. It also shows the apparent wind (yellow dashed arrow) at that same point at almost 50 degrees — close hauled, beating–OK if the swell and wind have been given a deeper assessment.

So when sorting through weather conditions, we prefer to see some south in the (less than 4 foot) swells (with at least 10 second periods) and some west in a true wind between 17 and 22 knots. It worked out that way this time. It was a magic carpet ride. We’ve had worse rides on the Bay. The only swell we punched through was just outside Port Everglades, and we think that was tidal flow mixing badly with Stream flow.

One thing we found interesting was we encountered a slight eddy just before the halfway point of the trip. It almost had us starting the engine sooner than need be. Another thing is while the harbor looks to have been modeled after a European Harbor of Refuge, there is a wicked side-set right before the jetties as well as a wind acceleration (when the wind is coast wise). We were back to crabbing 30 degrees for the last half mile. This is a good reason to line up ones approach early — to assess the set. Also Old Bahama Bay is down to short staff–one very capable and friendly dock hand who can’t always answer the first (or more) radio calls. Give him a break. Several folks didn’t.

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