Ah, the Gulf Stream. If you’re boating on the southeast coast of the US or heading to the Bahamas/Caribbean from the US, it’s a major factor in your navigation.
If you’re heading north, you want to catch it . . . and you hope it’s going fast. If you’re heading south, you want to try to catch a counter-current. And if you’re crossing to the Bahamas or Cuba, knowing the speed will give you an idea of how far north (for the Bahamas) or east (for Cuba) you’re likely to be swept.
There are a number of paid services for detailed information on the Gulf Stream. Probably the best known is Jenifer Clark’s Gulfstream and she will provide very precise routing information for cruisers as well as professional mariners.
The good news is that there is also a good source for free maps showing the location and speed of the Gulf Stream and counter-currents. The Gulf Stream maps from PassageWeather are not as detailed as the professional services, but I have always found these to be sufficient for our purposes.
PassageWeather is a free service, but they gratefully accept donations — if you find the maps useful, I’d suggest throwing in a dollar or two so that they continue to be available.
To get to the Gulf Stream maps for the rest of the East Coast:
Go to the PassageWeather home page. You’ll see a map that looks like this:
Click on the area that you’re interested in, and then another similar map will come up for just that area. Again, click on the area you’re interested in. Finally something that looks like this will come up — note the Gulf Stream tab.
Click on it and you’ll get a map with the stream clearly marked. Note the color differences for the speed (legend is at the bottom of the map) and the direction arrows for the stream itself and counter-currents.
Don’t rely on an old map or even the “approximate location” of the stream that is marked on most charts. The location and the speed of the Gulf Stream can vary a fair amount. When we crossed from Florida to the Bahamas in May 2016, the stream was almost immediately outside the Florida Keys and running over 3 knots, and 3.5 knots for a short while a little further out with a pronounced counter-current flowing almost due south near the Bahamas.
As I’m writing this, the Gulf Stream is further offshore of the Keys, running 1.5 to 2 knots, and the counter-current nearer the Bahamas is running southwest, not true south. All this makes a big difference in planning a passage!