Why a Strongall aluminium hull rather than steel?
Strongall aluminium, with high yield strength and 10 to 25 mm plating on the bottom, absorbs impacts without giving way, can be cold-repaired with the tools onboard, and does not impose the permanent fight against corrosion that steel does. For a long route in the South, it is the compromise that holds up.
Why a swing-keel design rather than a fixed-keel yacht?
Keel raised, draft drops to 1.3 m and gives access to the Patagonian caletas and to drying-out anchorages. Keel lowered, you recover 3.2 m of lateral plane to work upwind south of 60°S. The 5.2-tonne ballast sits on the keel itself, not on the hull bottom. Versatility and performance, not one against the other.
Why a cutter rig, with both genoa and staysail?
In heavy weather, you furl the genoa and unfurl the staysail without leaving the cockpit. Genoa for 0 to 30 knots, staysail for 30 to 45. Beyond that, you ride out under triple-reefed main or under storm jib. Most of the time, the cutter rig lets you reduce sail at distance, without putting yourself at risk.
Why two engines?
A recent 115 hp inboard replacing the original MWM, plus a 60 hp 4-blade outboard on the stern bracket. In the Patagonian channels, against katabatic wind and current, an engine that quits means the boat lying beam-on within thirty seconds. With two engines, you fight back upwind against current, you pull off a shoal, you escape an ice trap less than a metre across. Redundancy turns into useful margin.
Why an oversized tender?
A 2.60 m plastic tender does not survive a 100-knot gust, it flies away like a kite. ARION's tender is 4 m of aluminium, unsinkable, designed like a barge. Built by students at a vocational technical school in Chambéry, deployed and recovered by a derrick on deck. Backup escape route alongside the liferaft, kedging off a shoal, deflecting a bergy bit, ferrying jerrycans: matched to the boat.
1800 Ah of lithium, is that a lot or just enough?
South of 60°S, you draw 250 to 400 Ah a day across Starlink, radar, AIS, autopilot, supplemental heating, fridge, lighting. With 1800 Ah of usable LiFePO4, you hold three days without production in a windless, sunless storm. Beyond that, the diesel genset takes over. The real constraint is not capacity but cold protection: lithium chemistry freezes below 0°C.
How do you stay alive at −25°C inside a boat?
Three layers. Aluminium hull insulated with 80 mm of sprayed polyurethane, anti-condensation lining over the floors, wood interior cladding. 5 kW diesel forced-air heater, dedicated tank, 400 hours of autonomy. Backup heater on kerosene or wood, fully independent of the electrical system. Nobody dies of cold aboard ARION as long as there is fuel left.
Several weeks without a port, what about fresh water?
Watermaker at 60 l/h, 12 V motor, 6 A. We produce more than we consume even on overcast days. Buffer reserve of 600 l in two interior stainless tanks. Consumption 10 to 15 l per person per day: drinking, cooking, minimal hygiene, no shower. If the watermaker fails, the 600 l reserve covers twenty days for two. Beyond that, rationing and rainwater collection.
Is Starlink reliable south of 60°S?
Starlink Ocean covers the entire circumpolar zone via the inclined LEO satellites. Service gaps are more frequent south of southern South America and across some sectors of the South Pacific, but it works. Throughput 25 to 100 Mbit/s, enough for GRIB weather, emails, scientific data. Iridium permanently as backup: if Starlink drops, weather and emergency messages switch over automatically. Two orbits, two operators.
Ice at night, how do you see it coming?
Raymarine Quantum 2 Doppler radar, 24 nautical miles of usable range on large icebergs, 6 to 8 miles on bergy bits 5 to 10 m across. Below that, the radar sees little. Growlers, surface-flush chunks 1 to 3 m, are the real trap: no radar echo, not visible to the naked eye beyond 30 m. At 7 knots, ten to thirty seconds to dodge. Mitigation: reduced speed at night in ice zones (5 to 6 knots), constant visual watch, forward-looking thermal cameras under study.
What sails for heavy weather?
A simple, well-maintained wardrobe. Offshore mainsail with three reefs, kevlar reinforcements, fully droppable from the cockpit. 135% genoa on furler up to 30 knots. Staysail on furler from 30 to 45. Beyond that, a 6 m² storm jib hoisted on a removable inner stay, mainsail replaced by a trysail for running off bare-poled or nearly so. Storm-sail set stowed in a numbered bag, accessible without light. Rule: reduce before you have to.
Medical care at sea with a crew of two, how?
Three assets. Full sickbay, basic surgery, broad-spectrum antibiotics, major analgesics, immobilisation, defibrillator. Onboard medical competence with the Captain's medical training and Sarah's expedition medicine course. 24/7 teleconsultation via Iridium or Starlink, with a maritime medicine service taking over the complex cases. Knowing that south of 60°S, an evacuation takes several days.
Systems freezing at −25°C, how do you prevent it?
PTFE seacocks rather than brass, less seizing. Seawater piping sleeved and traced with heater elements at critical bends. Diesel treated against waxing from the equator onward, fuel circuit warmed. Batteries in an insulated compartment with a probe, charging cut off below 0°C. Fresh water in interior tanks. Watermaker stopped and purged between cycles to prevent membrane freezing. Each system has its own documented winter protocol.
Why depart from Marseille for Antarctica?
Marseille is the Captain's home port and the base of the ARION refit. Exit the Mediterranean via Gibraltar, descent of the Atlantic in the trade winds, shakedown stop in Cape Verde, then direct route toward Patagonia via Trinidad or directly depending on the weather window. Operational logic, not symbolic: you depart from where the boat is fitted out, and you treat everything that comes up on the way as a system test before the Drake.
How are watches organised with a crew of two?
Three-hour watches, strict alternation, twenty-four hours a day. At night, the active watch is in the cockpit or at the chart table, the resting watch sleeps in cold-weather gear, ready to take the helm in under a minute. Heavy manoeuvres are done by both, by waking the other. Hard discipline the first few days, indispensable beyond the second week at sea.
Sailing under the French flag, what difference does it make?
French registration, French SOLAS rules for safety, pre-departure audit by the Affaires Maritimes, French maritime law onboard. In practice: certified safety equipment, registered EPIRB, crew manual, medical log. At the end of the expedition, the file has to be closed administratively. Not a bureaucratic detail: it is the framework that makes the expedition recognised, therefore fundable and documentable.
Why Patagonia as a training ground before Antarctica?
Patagonia is the last terrain where a mistake remains recoverable. Katabatic gusts to 60 knots in the channels, tidal currents, exposed anchorages, glaciers nearby: it is already serious, but there are still ports, people, an Iridium link that connects to something useful. Past the Drake, a mistake no longer costs you time, it can cost you the boat. We spend in Patagonia as much time as needed, without trying to go fast.
Why not a single title sponsor covering everything?
A single title sponsor imposes its agenda: itinerary, calendar, narrative tone, mandatory port calls for marketing activations. South of 60°S, the agenda is set by the weather, not by an approval committee. The chosen model is multi-partner (Title, Technical, Targeted), with framed deliverables and decision-making independence preserved through the end of the expedition. Harder to assemble, more solid to execute.
What role does Sarah play beyond the science?
Sarah is an offshore-trained sailor since childhood before being a marine biologist. She holds her share of the watches, reduces sail, sails ARION solo for hours on end. If I am asleep or busy elsewhere, the boat does not stop. The science comes after, in the margins of the manoeuvre. That is what makes a two-person crew viable over the duration of a circumnavigation.