Gulf Stream navigation begins well before the race with a close watch on the evolution of the form and structure of the Stream across the route to Bermuda. By W. Frank Bohlen
With 30 days to go to the start of the 2018 Newport Bermuda Race, serious navigators are watching the Gulf Stream change and looking for clues to its probable evolution. As every year I sail this race, I have been watching, too, and have now written the first of a series of notes, shared on our Gulf Stream Tutorials page along with archival pieces written from 2002-2016.
As of this writing, in early May, the Gulf Stream crossed the Newport‐Bermuda rhumb line at a point approximately 240nm from Newport. Stream structure in the area of the crossing was dominated by a large amplitude meander that was displaying little tendency to migrate to the east. Maximum speeds appear to be on the rhumb line and within 30nm to the east. To the west, speeds drop off quickly with flow trajectories tracing a nearly circular pattern.To the south of the northern margin of the Stream, there was a cold-core ring centered nearly 120nm to the west of the rhumb line, which affected flows over much of the area east to the line.
These are just a few of the highlights. For much more detail, including an explanation of some of the available data sources and which ones are used by common routing program, read the full report.