In this article
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:
- 1 – 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.
- 2 – The anti-cyclonic eddy east of Gabo Island has moved further eastward, weakening southward currents in the coastal region.
- 3 – 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.
Related blog articles
Tidetech in Port Technology International: bringing water forecasting into port planning
Tidetech’s Penny Haire and Seb Mancini speak with Port Technology International about how high-resolution water-level and surface-current forecasts can help ports plan vessel movements with greater confidence, from S-100 trials to just-in-time operations.
S-100 gains momentum — what’s driving adoption, and what’s still missing
S-100 is gaining real momentum, though plenty of work remains before it becomes the global standard it's designed to be. We look at where progress stands, and the gaps still to close.
S-100 is a team effort — why hydrographic data standards depend on industry collaboration
S-100 adoption depends on more than standards alone. From data pipelines and validation to real-world testing, Tidetech explores why collaboration between hydrographic offices, technology providers and data specialists is essential to making S-100 work at scale.