Update

A couple of images from a busy shop. Our new website is nearing completion so more detailed info will be available soon, on our UAV work especially, as well as the ongoing foiling sailboat projects.

Limiting

Ongoing testing with different foiling configurations is confirming that ultimately righting moment will determine top speed.

The diagram below nicely illustrates what happens as speed builds.
The plot takes a constant true wind angle (heading relative to true wind direction). As boatspeed increases, the component of apparent wind from dead-ahead gets bigger, while the true wind velocity stays constant. Therefore the wind we feel on our sail moves progressively further forward.

Diagram taken from the interesting article here:
http://boards.co.uk/how-to/how-fast-can-we-go-the-science-of-speed.html#AmZd7dgCcvAEmL31.97

As apparent wind direction moves forward, we have to sheet on in order to keep an angle of incidence between sail and apparent wind. But moving the boom closer to the centreline increases the component of sail force that wants to heel the boat over. For the same sail force, drive decreases and overturning moment increases. Hence we need righting moment to resist the added heeling moment.

On the left we have the boom eased and the sail twisted. Sail force (orange) is mostly directed forward.
On the right the boom is near centreline and the leech is tightened by sheeting on.
In these diagrams sail force is identical but the component to leeward (responsible for heeling moment) is much larger when the apparent wind rotates forward.
In reality, when the apparent moves forward, it also increases in speed. So sail force would be larger, exacerbating the problem. 

It is inescapable that we must be able to get all our upward lift from our leeward foil if we ever want to be able to efficiently foil upwind. Also if we want to foil in light airs downwind, and if we want to keep pushing max speed downwind in fresher conditions.

Recent work with AC45 Turbo test platforms, and smaller cats, has shown that differential rudder rake, such that the windward elevator foil produces downforce, can add significant speed.
It may be that using the windward foil to pull down could pay, bringing about a return to four-point systems.
But it is certain that span restrictions that require multiple surfaces to get sufficient lift on the leeward side are driving development to a dead-end. If such restrictions persist, more changes are inevitable as people invent elaborate rule-cheats such as having several foils in each hull.
Much better to encourage simplicity.

Mostro del Garda

Congratulations to Marvin Baumeister for winning the Foiling Week regatta for kiteboards.
He used (for the first time) an all-new foil package (vertical, fuselage, and horizontals) created with project and design co-ordination by Carbonix. CFD and optimisation was by D3 Applied Technologies. Tooling design by Carbonix...

Critical Mass

Interest in our L foil kits has been overwhelming. We are at full capacity fulfilling orders and have additional tooling in the pipeline to shorten lead times. Will be sure to publish more images and detailed specs as soon as we get a chance.

Market demand speaks clearly and people are 'voting with their wallets'. Customers who want the best solution within the original A Class box rule far outnumber those willing to invest in complex rule-cheats, chasing a moving target.

Other manufacturers are also gearing up to match demand for ‘non Rule 8’ foils. A wise investment on their part. Having more products on offer is great. Whether competing or complementary at different price points, the result is more choice for the sailor and a healthier fleet.

Solutions by manufacturers and private builders don’t just include L/V inserted-from-below designs, but also Z/Hydroptere type foils with longer span and less tortured angles. 

Every configuration has strength and weaknesses. Personal preference plays a part and competition will further inform us on how the performance envelopes overlap. What they have in common is the pursuit of efficiency unshackled from arbitrary chains.

For now this means we are heading to the absurd situation of a majority of boats being considered illegal in official events. Naturally the result would be reduced participation. Fortunately initiatives such as that spearheaded by the USA and Canada are smoothing the road for a sensible adjustment.

Leading sailors have expressed their support. Those who have experimented and want others to share the experience are in favour of allowing the design freedom to make foiling easier and safer.

Every A Class sailor must now be sure to make their vote count. Let our elected committee members fairly represent the reality on the beach and finally allow progress to flow.

Pic courtesy Sentient Blue Team showing a 2007 A Class platform retrofitted with Carbonix 2014 foils and rudders.