SailGP Germany: What is causing the SailGP damage - how does it compare with F1?
by Richard Gladwell/Sail-World.com 19 Aug 04:50 PDT
Great Britain hull damage - Day 1 - Sail GP Germany - August 16, 2025 © Felix Diemer/SailGP
SailGP had a weekend to forget with four teams suffering significant damage - serious enough for two to miss some or all the racing.
Significantly the SailGP Technologies shore support team was able to effect major repairs overnight to get the other two of the damaged teams back racing.
Arguably the weekend was probably the most destructive since 2023, when the Kiwi team suffered a lightning strike in Singapore requiring a complete re-wiring of their F50. That was followed by a more destructive incident at the next regatta in Sydney in February 2023 when a whirling wind hurled the Canadian team’s wingsail into a tent of stored wingsails and the damage forced the cancellation of racing for the second day of the regatta.
Earlier this year the Brazilian leg of SailGP's Season 5 was cancelled after the Australian team dropped a wingsail in moderate wind during racing in San Francisco. A timeout was called so all boats could be checked and repaired if required. Aside from the major repairs to the Australian wingsail, the shear webs (wingsail internal framing) were upgraded in several wing sails.
The six boats from the fleet that started out as the near one design AC50 at the 2017 America's Cup, have been converted to F50s a pure one design - all owned, upgraded and maintained by the league. Six new F50s have been built, another two are under construction. Each comes with three rigs and a fourth is being added. The wingsails are built up from a choice of five wing pieces. Then there are light air foils (similar to the 2017 AC), and now T-foils which are the General-purpose foil. Light air and high-speed rudders are used. A light air rudder replacement, and light air main foils are being introduced replacing the 2017 gear.
Add up the various components and that is a lot of gear to be checked and maintained, by a single support team.
Cavitation continues to be the enemy of the foilers, where water in a low-pressure area of the foil reaches boiling point, the bubbling water builds across the horizontal part of the foil surface, lift breaks down and some extreme boat behaviour is the inevitable outcome. There are three reasons for continuing to push out the performance boundaries. The first is so that the gear is all essentially the same and to a design specially purposed for SailGP i.e. on foils they consist of two parts - a horizontal foil of varying sizes, which can be quickly bolted onto the bottom of a common vertical component. This is a significant from the L foils used in the 2017 America's Cup and through to the start of Season 5.
Secondly all components have a common birthday - much easier for scheduling maintenance and routine checks. If the foils can be designed to have a higher speed when cavitation clicks in, it follows that at lower speeds cavitation becomes a flight controller, or crew induced issue, rather than a phenomenon that is inherent in the design.
In Germany we saw the highest speeds recorded during racing, with two F50s topping three-digit speeds (in km/hr) in Germany, and most of the fleet getting close. More importantly none of the F50s spun out/nose-dived as a consequence of reaching those top end speeds. Clearly the F50s are now faster at top speed, than the AC75s used in the America's Cup. However, the F50 is a flat-water boat, and can't foil as safely as the AC75 in bigger sea states.
Despite the time out called for the fleet after the Australians rig snafu in San Francisco, the French dropped their wingsail on Day 1 in Portsmouth, losing the day but were back up to speed for the second day of the event. Fortuitously the SailGP Technologies build facility was just up the road - but that is not usually the case, and the SailGP shore team must be very well-organised and self-sufficient.
Only one regatta intervened, New York, without an F50 had a wing sail breaking, which usually occurs on a section join.
Below is a selection of images of damage from last weekend at SailGP Germany, along with a video from Athena Racing, showing how Emirates Great Britain was repaired using a sacrificial piece from the hull of the USA F50, which was laminated into place on the British boat.
In both cases, and others, the repair technique is impressive in its speed and is very skilful. The patch for the hole entails either using a sacrificial piece as was done in the weekend or constructing a new section using the original or new tooling, so the external hull shape is identical to the original.
Ironically, the British America's Cup then sailing an AC50 sustained similar damage on the first day of racing in the 2017 Challenger Selection Series in Bermuda, when they slid sideways into Softbank Japan damaging the deck of the Japanese boat, and putting a big man-sized hole in their own. It too was repaired overnight by the shore support team.
Also included are some shots from a media tour of the SailGP Technologies 65,000 sq. ft Southampton facility, showing new components either finished, or under construction. At the time a set of new 16 wingsails, including two spares, were under construction permitting a 27.5metre wing sail to be used in November, ready for the start of Season 6. The top and bottom wingsail sections are constant in any rig configuration, with the intervening sections being added to achieve the required rig height ahead of each race day.
In mid-July, a new F50 was near finished construction, with a second to be started, for the league expansion by two new sailing teams. An inventory of spare parts, including two spare boats, is also being built up. The construction of one boat requires 40,000 man-hours, with 35-40 individuals working full-time for 8-9 months.
In looking at the damage from the weekend, operator error was the cause in most, if not all, of the incidents
The loads on the boats are already high. During the rigging process the forestay is tensioned using a hydraulic ram. All stays are pinned exerting a force of 21 tons on the main beam. What happens with that load, and if it increases, during violent sailor-created nosedives is anyone's guess.
Catastrophic failures can be attributed one of two reasons - either the part/structure is not strong enough, or the load was too high. To try and understand the racing loads, strain gauges are positioned at critical parts of the F50 - which provide 4.4billion data points (a similar number to an F1 race car) each race day for analysis and tuning of the structural analysis software.
The issue with the F50s is that to improve the speed and handling by various means, the design teams are operating at the frontier of race boat performance.
In comparison with other high-speed sports, the rate of failure in the SailGP is a lot less than in Formula One racing - where the performance envelope is also pushed very hard, and the rate of operator (driver) error is high. However, that is accepted as being part and parcel of the sport.
In F1, 60-70% of the DNFs are attributed to driver error; 20-30% are technical (design and race car set-up); racing incidents account for 10%
Dramatic failures, while not a good look for the League, are unfortunately part of the learning experience in the quest for speed.
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