The 80th Rolex Sydney to Hobart is almost here. For sailors, this race is never just about wind angles and sail changes. The ocean itself is a player — this year it’s shaping up to be an intriguing one.
To understand what’s going on with East Australian Current and other water movement along the route, Tidetech’s chief scientist Roger Proctor has the analysis:
“The East Australian Current can help or hinder your progress to Hobart. Each year the scenario is different, and sailors need to juggle the metocean conditions to their best advantage. Right now, we’re seeing a strengthening southward current from Wollongong to Jervis Bay, thanks to a split in the big anti-cyclonic eddy off the coast.
“Looking at the ocean current at the beginning of December and comparing it to 21 December, we can see several changes ahead of the race — here are three points of interest:
- The large anti-cyclonic eddy seen on 1 December has split into two eddies with the smaller now closer to the coast. This implies strengthening of southward current from Wollongong to Jervis Bay.
- The anti-cyclonic eddy east of Gabo Island has moved further eastward, weakening southward currents in the coastal region.
- The anti-cyclonic eddy east of Tasmania has remained static, providing some southward current off north-east Tasmania.
The finish is key as usual
“On the approaches to the Derwent Estuary, there’s a northward current between Freycinet Peninsula and Tasman Island, and across the mouth of the estuary itself (part of the Zeehan Current). Combine that with spring tides early in the race and you’ve got a tactical puzzle that will reward sharp eyes and smart routing.”
Roger’s advice? Keep watching the ocean. These eddy features are evolving slowly, so conditions on race day should look much like they do now. But small shifts can matter.
A big shout-out to the Integrated Marine Observing System (IMOS) Ocean Current team for the imagery that makes this analysis possible. Their data is invaluable for understanding what’s happening beneath the hull.
For sailing competitors, Tidetech’s high-resolution models and GRIB files are available now. Because in this race, knowledge isn’t just power, it’s speed.
Head to sailing.tidetech.org/pricing and subscribe to the advanced package (then look for 'Global Combined Currents' and 'Derwent Currents' to download GRIB files for your navigation software.)
