RORC Caribbean 600 – Navigators' dreams & nightmares
by Louay Habib/RORC 21 Feb 11:37 UTC
24 February 2025
`A quintessential race of wind side-effects` says Alexis Loison, navigator on Philippe Frantz's NM43 Albator (FRA) © Tim Wright / Photoaction.com
The RORC Caribbean 600 is a navigator's dream and nightmare rolled into one. A race that demands expert decision-making, fast thinking and a deep understanding of offshore tactics. With a wide fleet of boats racing this year, read the enlightening comments on the race by Nikki Henderson skipper of J/122 El Ocaso, Alexis Loison navigator on NM43 Albator and Will Oxley navigator on TP52 Summer Storm.
Complex Course & Constant Decision-Making
Unlike traditional offshore races with long, open-water stretches, the RORC Caribbean 600 weaves through 11 Caribbean islands, creating a constantly shifting tactical challenge. Navigators must plan for a myriad of sail changes and brutal wind and sea transitions shaped by the islands. Nailing the waypoints is crucial to maximise speed and reduce manoeuvres.
"The RORC Caribbean 600 is the quintessential race of wind side-effects," commented Alexis Loison, navigator on Philippe Frantz's NM43 Albator."It's essential to thoroughly analyse the topographical details of each island before the start, to understand how the wind shadow will behave. Hour of the day is also a clue; I have found that the wind shadows are not the same between day and night." continued Loison.
Nikki Henderson skipper for the charter guests on J/122 El Ocaso has done the race three times before, coming second in class in 2020. Her El Ocaso crew are nearly all amateur sailors, but between them they have raced the '600 12 times. "We haven't looked closely enough at the forecast yet, but probably sometime around 4 days will be our elapsed time. What's going to affect that? - making it through Guadeloupe, of course, like everyone. Keeping pace on in the upwind legs, which are definitely our strong suit in our class. We need to hope that we can hold our ground on the reaches and will be shooting for the shortest distance on the course wherever possible," continued Henderson.
Wind Shadows & Island Effects
The islands create significant wind shadows and acceleration zones, forcing navigators to make critical routing choices. Guadeloupe in particular is famous for its foreboding wind hole, so do you risk playing it safe offshore or do you go right into the 'Guadeloupe Casino'?
Alexis Loison: "Last year, at sundown, the boats that made good gains went offshore at Guadeloupe. But at night, it was the boats inshore that made the best route."
Guadeloupe is not the only wind shadow on the course. Nikki Henderson highlighted Saba Island for good reason; El Ocaso will have the advantage of seeing the weather effects of boats in front of them. "Rounding Saba is always an interesting choice - to play the corner and the curve of the wind round the north tip of the island and hugging the coast before heading up to St Barth's can often be advantageous. But the wind can also be light down there. We will be keeping an eye on how the boats ahead fare," explained Henderson.
Squalls & Sargassum
The Caribbean trade winds can be steady, but squalls bring intense bursts of wind and rain. The navigator's dilemma is to decide whether to avoid them or use them, and sometimes, there is no choice. Sargassum Weed floating in clumps have been prevalent in the Caribbean for many years, while Sargassum has both positive and negative effects on the ecosystem, it can be a nightmare for teams in the RORC Caribbean 600, as Will Oxley explains:
"Sargassum has created headaches for crews as it wraps itself around the foils, often necessitating a time consuming backdown. The latest thinking is that there is now a source population in the Atlantic that seasonally goes into bloom. It is believed that increased nutrient runoff flowing out from the Amazon and the Congo Rivers plays a role in these blooms."
Alexis Loison: "Managing trade wind squalls is crucial in this type of race. First, it is essential to anticipate their arrival and adjust your course to benefit from the best angle and wind strength. You need to anticipate and not just react. Significant gains can be achieved. Another important aspect is to anticipate the adjustments and choice of sails to avoid damaging equipment."
Nikki Henderson on squalls: "We will be monitoring their tracks and aim to stay the best side of them to take advantage of any useful shift if we can't avoid them. Preparing for them is just about being able to change sails quickly - it's a long race and making the least mistakes is more important than cutting a squall super fine. Without a moon this year, seeing the squalls at night will be more difficult. We are making sure we get in a full night sail this week in preparation. After all... 50% of the race is in the dark."
Will Oxley: Reading Clouds
Wil Oxley has competed in three previous editions of the '600 with Juan 88 Lucky, Volvo 70 Wizard and VPLP 100 Comanche. Will has a detailed video on navigating for the RORC Caribbean 600 on his website, and says it is important to look for convergent clouds.
"Clouds provide a good indication of wind direction. Winds wrap around both sides of the islands and come together on the leeward side. Moist air rises, causing a convergence cloud. People often talk about sucking or blowing clouds.
A sucking cloud refers to strongly rising air currents. Indicators are rapid vertical development with the cloud visibly growing. Darker cloud bases with crisp edges can indicate lots of moisture being drawn into the cloud.
Blowing clouds produce strong descending air currents. These blowing clouds can be identified by diffuse or ragged bases, the presence of virga (rain that has not reached the surface), and in more extreme cases a cumulonimbus cloud with a large anvil top. Sounds simple, but sometimes clouds are both sucking and blowing at the same time. Often you learn from the first cloud what is going on."
No Such Thing as a Perfect Race
The RORC Caribbean 600 is a race of damage control, quick thinking, and adapting on the fly. Success often comes down to minimising errors and reacting faster than the competition. Sometimes the right call is simply down to trusting instincts.
Alexis Loison will be competing in his 19th Solitaire du Figaro later this year. He has finished nine times in the top 10 and won class in the Rolex Fastnet Race five times, including an overall win in 2013, racing double-handed with his father Pascal.
"No offshore race can be executed perfectly from a strategic point of view," concluded Loison. "It is constantly a subtle game of decisions, compromises, race and boat management, etc. And the best school for learning to manage all these strategic parameters is undoubtedly the Solitaire du Figaro!"
Final Verdict: A Navigator's Ultimate Test
The RORC Caribbean 600 is one of the most dynamic, unpredictable, and challenging offshore races in the world. For navigators, it's a high-stakes chess match on the water, requiring skill, intuition and resilience. This legendary race attracts a huge range of race boats and sailors from across the globe.
"The RORC Caribbean 600 can never be perfect," commented Nikki Henderson. "I'd say, a race where there is almost an indefinite room for improvement is like an addictive drug... you keep wanting to come back for more."
The RORC Caribbean 600 starts on Monday 24th February from Antigua. For more information and to follow the race, go to: www.caribbean600.rorc.org