/ 
A serial solar-powered catamaran crossing the Atlantic is no longer a promise, it's a fact. At the end of 2025, the Silent Yachts SY62 â??100%â? sailed from Gibraltar to Antigua in 4 weeks. Here's what this navigation says about the reality of electric catamarans on the high seas.
Real solar autonomy on a transoceanic cruise
A 5,300-nautical-mile crossing, mainly powered by solar energy. The route set out from Gibraltar, with technical stopovers in Casablanca, the Canaries and Mindelo, before embarking on a crossing of over 2,100 nautical miles to Guadeloupe. SY62 sailed at an average speed of 5 to 6 knots, with occasional peaks of 8 knots when energy conditions allowed.
Solar output varied from 45 to 60 kWh per day, depending on sunshine and panel orientation. In all, almost 1,400 kWh were generated by the panels during the crossing. This covers a good part of the ship's needs, estimated at between 350 and 600 kWh per day, depending on speed, weather conditions, domestic comfort (hot water, cooking, audiovisual) and the operation of auxiliary systems (pumps, lighting, ventilation).
Details of on-board electrical system
An energy architecture designed for redundancy and endurance. The SY62 is based on four technical pillars:
- High-efficiency solar panels on roof and flybridge, generating up to 60 kWh/day
- LFP (lithium iron phosphate), liquid-cooled batteries for improved thermal efficiency and longer life (claimed life cycle in excess of 6,000 cycles)
- Emission-free, liquid-cooled electric motors delivering 2 x 150 kW rated power
- Emergency diesel generator used only for battery recharging, with marginal consumption (estimated at less than 10% of total operating time over the 4-week crossing)
All systems are supervised by a centralized, remotely accessible monitoring module, with continuous logging of production and consumption.
Generator use: an accepted compromise
Minimal fuel consumption, but not zero. Unlike a totally carbon-free unit, the SY62 carries a thermal range extender (generator), used only as a last resort. This generator remained on standby for much of the time, being activated for a few hours on certain days of dense cloud cover.
The shipyard has not yet published the final consumption figures, but according to on-board accounts, consumption was less than 150 liters over the entire crossing. For a 30-ton catamaran, over a 4-week transatlantic crossing, this is still significant.
Navigation performance: between reasonable speed and fuel efficiency
Hydrodynamic efficiency remains key to the overall system. At 18.90 meters long and 8.67 meters wide, the SY62 Open 3-Deck features a submerged surface area optimized to reduce drag. The hull is specifically designed for slow displacement, at around 5 to 7 knots, which remains the optimum zone for electric autonomy.
- Optimum cruising speed: between 5.5 and 6.2 knots
- Maximum speed reached (with assistance): around 8 knots
- Range in purely solar mode: variable depending on weather; estimated at 100-150 miles per day
- Range with range extender: depending on tank, but estimated at 1,200 to 1,500 miles without solar recharge
Comfort and ergonomics at sea
A catamaran designed to last at sea, not to shine on the pontoon. The SY62 3-Deck Open favors open spaces: an uncluttered flybridge, an open-space galley, bright, airy cabins and wide, well-protected decks. The layout is designed to allow a reduced crew to live aboard, without dependence on a marina.
The electrical system provides uninterrupted power :
- Refrigeration, freezing, washing machine
- Kitchen equipment (induction hob, electric oven, dishwasher)
- Air conditioning, ventilation, LED lighting
- Hot water, bilge pumps, pressurized water
Technical observations and feedback
A system that requires discipline, but not technical expertise. Feedback from the crew is clear: the systems are robust, but require discipline and anticipation. Permanent monitoring of consumption and production is becoming as much a reflex as watchkeeping and weather reports.
The catamaran also tested auxiliary propulsion systems, including a kite sail under development for experimental use. No figures are yet available, but initial feedback is encouraging for downwind sailing.
