We’re sitting calmly at anchor at Turtle Cay in the Abacos. There’s a low sky rolling quickly by and the breeze is howling in our rigging (such as it is). Not conducive to wanting to leave. However, we’ve found that conditions in the ocean rarely match what the subconscious conjures at anchor, if we just push that button and lift the anchor.

This is the forecast which is valid early this evening. We have downloaded current weather, and the wind/wave, synoptic, and 500mb data out to 96 hours. These all tie well to both GFS and NOGAPs weather models, giving us confidence in the Expedition routing data below.

Using Sailmail and Saildocs we have downloaded both GFS and NOGAPs weather models out for a week, We have also downloaded the ROTFS current model for the region to be traversed. Expedition will combine the ocean current data together with wind and our performance polar.

Both GFS and NOGAPs are in close alignment on wind speeds and direction.

Here is the data for GFS + ocean current information starting at 1000 Eastern Standard time. The two key elements are true wind speed (TWS) and true wind angle (TWA). The wave angle has a major impact on comfort. In this case, GFS is projecting winds around 45 degrees off the bow. If this is actually the case (and the way we are lying at anchor confirms this for now) Wind Horse will barely feel the seas.

This data goes out for the full passage to Lunenberg and projects a passage time of a hair under five days with weather improving (getting calmer with the wind clocking behind us) as we progress up the track.

When you look at the data for a Tuesday departure it looks even more favorable for the first leg. Winds are clocked more on the beam and lower in velocity. However, we can comfortably deal with what is expected today, and are more concerned with unforecast lows spinning up three or four days from now. So, off we go (subject to changing our minds, of course, once we get our snoot into the Atlantic).

This is a graphical representation of the three routings and the projected track (red is GFS leaving this morning). Under sail, the track would show more of a sag to the west once clear of the Bahamas. This would keep you reaching (faster) and allow you to come back onto the wind a bit as the breeze lightened and clocked.

Amazing tools we have these days. And, all this data was downloaded off the Internet at anchor, essentially for free, except for the cost of belonging to Sailmail.

We close with one caveat. These weather model GRIB files are great. But they are raw data, untouched by folks with experience. Sometimes they work and sometimes they miss things. There are areas in the world where they work better than others. Any passage which involves continental and marine influences, coupled with ocean current with a temperature differential is going to increase the rate of model mistakes. This is where the duty forecaster at the local Met. office comes in, and where your professional routers earn their fees. These folks can look at a variety of models, along with many other sources of info, and then combine what they see with experience and gut instinct. So, cool as all this is, it is only one piece of the puzzle.