When super maxi Master Lock Comanche swept across the line to claim line honours in the 2025 Rolex Sydney to Hobart, the spotlight naturally fell on the hundred footer's size, speed and crew work. But deep in the background was the quiet, methodical craft of Andy Green, the boat’s navigator and one of the most respected technical brains on the international racing circuit.
Green is not the sort of navigator who emerges from a darkened nav station to declare a single, heroic tactical call. His work is slower, more computational, and grounded in a blend of meteorology, data analysis and patience.
When we spoke with him in early February, he was just wrapping up a rare break in Sydney before moving to the UK to embark on a 2026 calendar that looks as if someone accidentally combined two professional sailors’ schedules.
We wanted to ask about how he uses Tidetech’s oceanographic data to win races. One thing came through clearly.
“Tidetech is essential,” he said.
“It’s the most accurate tidal modelling I’ve come across.”
This is how a modern navigator uses tides and current for success.
Green fell into navigation young. Around eighteen, he found himself with a deck screen thrust into his hands aboard a Farr 40 in Sydney. ‘Here you go, have a try at this,’ was the loose instruction. It stuck.
While he was honing his sailing in match racing, he also found himself drawn to bigger, more technical boats offshore, especially the competitive TP52 fleet that dominated Sydney’s blue water scene a decade ago.
“I was lucky," he said. "You had people like Will Oxley around. You couldn’t put a foot wrong. It pushed me to learn the science properly.”
That curiosity led him to study a naval architecture degree. Then, when the pandemic stopped racing entirely, he went back to university, this time for meteorology at Penn State.
Today, he speaks about navigation less as a seafaring art and more as a form of applied engineering.
“It’s almost like being a race engineer in motorsport,” he said.
“You’re building a model of the boat, feeding in weather, currents, polars… trying to eliminate uncertainty at every step.”
For many club sailors, a navigator is simply the person who keeps the boat ‘off the bricks’. For professionals, that ‘safely A-to-B’ role is still essential, but the full job is closer to running a live scientific experiment while bouncing round inside a barrel in a waterfall.
Green breaks it down like this:
“Sometimes the models are spot‑on, other times they’re wildly different,” Green said.
“Your job is to know which tools you can trust at any given moment.”
That’s where tides and currents become decisive.
In the 2023 Fastnet Race, Green recalls 40 knots of wind blowing against 3–5 knots of current off Portland Bill.
“It created these horrible, boat‑breaking seaways,” he said.
“We spent the first six hours of the race just trying not to destroy the boat.”
Likewise, in the 2025 Sydney to Hobart, the hundred‑footers discounted the offshore route where a helpful two‑knot southbound current was available.
“The southerly against that current would’ve given us three‑metre, near‑square waves. You can’t win the race if the boat doesn’t survive the first day.”
In both cases, currents shaped the strategy. But to make those calls, you need to trust the data. And that’s where Tidetech appears repeatedly in his toolbox.
Green’s endorsement is not casual. When discussing his use of Tidetech in the Admiral’s Cup, he doesn’t hedge.
“We won a race or two in the Admiral’s Cup because of Tidetech’s modelling,” he said
He is painstaking about model validation, which makes the comment all the stronger. During the event, the teams he was supporting studied three competing tidal models for the Solent and English Channel. Each was tested against the yacht’s measured set and drift, checked against SST imagery, and observed at times of maximum tidal complexity.
“We kept coming back to Tidetech,” he said.
“It was consistently the closest to reality — within about five degrees of the yacht’s set, and within 0.1 knots of drift.”
That level of precision isn’t theoretical. It produced race‑winning decisions in the inshore series. At one point, Green and a rival boat were the only crews confident enough to sail a minute-and-a-half past the ‘live’ layline — because the Tidetech Grib file showed the accelerating Solent current would sweep them back exactly to the mark. It did.
“Those are the moments you win races,” he said. “When your tools are right.”
Although Green spends most of his time on big offshore programmes, he’s quick to point out how Tidetech helps in places that flummox even experienced sailors.
“Hamilton Island Race Week and the Whitsundays are complicated,” he said.
“People really appreciate having [the tidal data] there in an easily readable format. It just takes so much confusion out of it.”
The waters around the islands can behave in ways that local memory and tide tables simply fail to predict. For many sailors — especially those stepping up from club racing — having a clear graphical view of what the water is doing becomes a genuine competitive edge.
[See Andy interviewed at the 2024 Hamilton Island Race Week talking about Tidetech — by Bow Caddy Media]
It’s easy to assume that elite navigation requires racks of hardware and custom systems. In truth, Green’s workflow spans from high‑end modelling software to simple, practical aids.
At the top of the stack is Expedition, which he says remains “a vital piece of kit”. He augments it with weather tools, ocean models, performance suites, and third‑party analytics. Larger programmes, such as America’s Cup or SailGP‑derived race simulators, feed into his broader preparation.
But he is quick to point out that the fundamentals scale down.
“For weekend racers, you don’t need the whole setup,” he said.
“Even a simple visual reference, like Tidetech in a browser window, gives you an edge. If you know there’s three‑tenths of a knot running one way, or that it’s uniform across the course, that’s already better information than most people have.”
He notes that he still uses PDF current charts or printed tide booklets when needed. Sophistication is sometimes optional, knowledge is not.
“Tides matter. The more accurately you can model them, the more certainty you have. That’s why Tidetech is part of everything I do.”
If the Hobart win looked like a career high point, 2026 suggests otherwise. Green is about to move to Norfolk, England to be closer to the European circuits. His calendar is a sprint.
He’s supporting an Etchells world championship campaign in San Diego, has races in Sardinia, Sorrento, Palma and Saint Tropez, is joining a J Class programme aboard Rainbow, continues development work for the 2027 Admiral’s Cup, and is expecting to compete in the Aegean 600. [Editor’s note: The Aegean 600 looks amazing! Check out this video.]
“It’s probably too much,” he admits with a laugh. “But I’m very lucky.”
Andy’s 2026 programme: