Weather Routing for Passagemakers

We just got back from a short four-day delivery of a friend’s 60-foot sloop from Bermuda to Newport, Rhode Island, a distance of 635 miles. In early May, weather along this route is always chancy and it was for us, too. On the Saturday that we were to depart, the forecast called for strong headwinds along the northwesterly rhumb line route followed by a strong cold front and even stronger winds. Ugh.

We had two weather forecasting, routing programs onboard the boat’s laptop computers, MaxSea and Predict Wind, which showed us the forecast and tried to route us through this mess of wind. We downloaded data via the boat’s Iridium satphone. MaxSea wanted to send us north and then had us beating into the northwest wind. It didn’t factor in the approaching cold front so it had us at sea and in the Gulf Stream when it was to pass over us. Not good. Predict Wind was more inventive and took us well west of the rhumb line on a close reach and across the Gulf Stream off Delaware Bay and then north to Newport. This looked promising but left us uncertain as the weather was changing hourly.

To get a professional opinion, we called Commanders’ Weather in New Hampshire for their recommendations and routing. They came back with an even more radical plan; they routed us on a beam reach west from Bermuda almost toward Charleston, then had us cross the stream off Hatteras before turning north in calm weather and with the wind behind us. With fingers crossed we set off from St. George’s, Bermuda and followed the Commander’s route with a bit of Predict Wind thrown in. It worked. While the wind raged along the rhumbline, we skated right around the back of the system with fair winds and fairly calm seas. We arrived in Newport in three days and 20 hours, having sailed 785 miles, or 150 more than the rhumb line—a good delivery time given the conditions and a very pleasant sail thanks to Commanders’, Predict Wind and a bit of MaxSea. Check them out at:, and

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