ILCA Announces New ILCA 4 MkII Sail
by ILCA Class Association 3 Feb 01:49 PST
ILCA fleet. Sun Hung Kai & Co. Hong Kong Race Week 2026 © RHKYC / Guy Nowell
The International Laser Class Association (ILCA) announced the upcoming launch of a redesigned ILCA 4 sail. The new ILCA 4 MkII sail was developed to strengthen long-term supply and improve durability without changing the ILCA 4 rig or compromising the ILCA one-design principle.
Why a new ILCA 4 sail?
For many years, the ILCA 4 sail has depended on a 3.8 oz sailcloth that is no longer produced at scale. This has created ongoing supply uncertainty and cost pressure for builders and sailors. If left unresolved, these constraints would increasingly affect availability—particularly within the ILCA 4 youth pathway, where consistent global access is essential.
"As the custodian of the ILCA Build Manual and the one-design integrity of the Class, ILCA has a responsibility to act when a material risk emerges," said Santiago Sampaio, ILCA's Chief Technical Officer. "Our design brief was clear: secure reliable long-term supply and maintain cost stability while preserving fairness, continuity, and compatibility with the existing ILCA 4 rig."
A controlled redesign
ILCA's technical evaluation confirmed that a direct replacement of the legacy cloth within the existing sail design would not deliver the desired results. Modern sailcloth styles have different properties and a like-for-like substitution risked variability and performance inconsistency across production runs and material batches.
ILCA therefore initiated a controlled redesign with clear constraints: same mast and boom, secure cloth availability, consistent manufacturing, and unchanged one-design integrity.
When will the new sail be available?
Commercial release of the ILCA 4 MkII sail is planned for early April 2026, with an initial controlled release to ensure fair global distribution amongst all ILCA Regions. ILCA's intention is for the sail to become class legal in early August 2026, in time for the ILCA 4 World Championship, subject to final confirmation. The current ILCA 4 MkI sail will remain fully class legal.
What's new with the ILCA 4 MkII?
The ILCA 4 MkII uses a more robust 4.93 oz cloth and adopts a bi-radial construction better suited to modern stiffer materials. Additional updates include:
- A larger sail window
- Standardized reinforcement patches
- An updated batten configuration, aligned with the MkII sail family
- A look-and-feel closer to the ILCA 7 MkII, improving consistency across the MkII range
These changes are intended to improve durability and consistency while minimizing the impact on costs.
Development and approval process
The sail was developed with the oversight of the ILCA Technical Team using CAD-based design, controlled prototypes and a two-phase testing program involving builders, sailors and coaches across regions, conditions and weight ranges. Feedback was systematically gathered via the ILCA Database App, which guided final refinements to shape, control response, and handling.
World Sailing was involved in the project from its early stages, including regular technical exchanges throughout the development phase. World Sailing subsequently reviewed the testing data and ILCA's comprehensive approval recommendation, which was approved and formally signed off in accordance with the applicable equipment approval policies.
Performance and sailor guidance
Overall performance remains comparable to the existing sail. Sailors report slightly improved responsiveness and a wider usable range, with additional camber available for lighter conditions and a greater ability to depower as the wind builds. The target sailor weight range remains 55-65 kg.
The MkII sail places greater emphasis on sail controls to tune the sail effectively, addressing a commonly raised limitation of the current ILCA 4 sail. As with the ILCA 7 MkII, sailors may benefit from higher Cunningham purchase ratios to fully access the sail's depower range.
Feedback from testing
Feedback from sailors and coaches involved in the testing program has been strongly positive:
ILCA 4 Coach - USA:
"The ILCA 4 sail tests are going really well. From my point of view, the new sail seems to be faster than the previous one. Its shape provides more tuning options, and it has everything it takes to become a big success."
ILCA 4 Sailor - Europe:
"The new sail feels really great - I think it can make the ILCA 4 even faster than before. It holds its shape really well so the power stays consistent while sailing, which makes the boat easier to push to its limits. For the ILCA 4 class, this feels like a big step forward and a really exciting improvement."
Other ILCA Development Projects
For the same reasons that have driven the evolution of the ILCA 4 sail, including long-term sailcloth availability and supply continuity, ILCA has also commenced work on the development of a future ILCA 6 MkII sail. This project is at an earlier stage than the ILCA 4 MkII sail and remains under development.
ILCA and World Sailing have come to the agreement that the existing ILCA 6 sail will continue to be used throughout the current Olympic cycle, including the 2028 Los Angeles Olympic Games and all qualifying events leading up to the Games. Details regarding the ILCA 6 MkII sail, including its development progress and any future introduction, will be communicated as the project develops.