Foiling Cats offshore

[donradcliffe]

The recent America's cup has proven the speed potential of foiling racing catamarans, so the next logical stepwas foiling cruising catamarans. The first development was the Gunboat G4 in 2015, which ended in a capsize in moderate winds:

https://vimeo.com/125378004

The next step was turboing the Gunboat 66 H20extreme in the 2015 Transpac:

“The most significant design changes from a stock GB66 are the 4.3m deep “C” foils that provide nearly 4 tons of lift at 20 knots of boat speed, a generous sail plan that allows us to fly a hull in as little as 12 TWS, a rotating mast with a cross beam and longeron all built by Southern Spars that allow us to carry up to 8 tons of luff tension on our furling sails"

The crew of H2) extreme was leading the other (nonfoiled) Gunboat until one late night squall in the middle of the Pacific, when they came VERY close to losing the boat. After that incident, the profesional crew backed way off on the sailplan every night and conceded the race to (the non-foiling) Phaedo.

The latest entry into offshore foiling cats is the 46 ft F4 from DNA, and here is a summary of their trip from New Yorkt to Bermuda

The Ultimate 'Thrillionaire' Experience >> Scuttlebutt Sailing News

The crew (including Jimmy Spithill and Shannon Falcone) saw God on the second day and reefed the boat down to under 200 miles/day:

“We went from pushing the boat for performance…into survival mode,” said Spithill, after arriving at ORACLE Team USA’s base in Bermuda. “These were the biggest waves I’ve faced in a multihull and hopefully don’t ever have to experience again.”

So, anybody still want to put foils on their cruising cat?? Or is the jury still out, waiting to see how the foiling IMOCA's do in the Vendee Globe?

[belizesailor]

Great fun on a race boat, but not for me on a cruising boat.

Last year for example we were sailing thru San Blas, Panama...loaded with shoals and reefs to keep you alert...nice breeze, making 7.5 kts, reefed...wife asked: why dont you shake out the reef? "Because, I dont want to go any faster!"...I ways already plenty busy eyeballing and navigating at 7.5 knots. Imagine on a big foiling cat...slowing down could be a challenge.

At higher speeds it gets more interesting. I used to race on a Corsair F31, easily capable of 20 knots. Ripping thru areas of shoals kept me, the navigator then, VERY busy...and a mistake would have been really ugly.

No thanks.

[Bleemus]

I did a fast run in a non-foiling trimaran to Bermuda. 59 hours. The foil boats look fun but the increased workload is not my cup of tea. Imagine a retired couple cruising in one? LOL

[Suijin]

I think Spithill's comments about sailing the F4 to Bermuda sum it up. "It's the next wave in offshore performance sailing, but there's a limit." Performance sailing and cruising are miles apart. No, your "performance cruiser" is not what he's talking about. The fact that the F4 had to switch to "survival mode" in a sea state where your average ocean-going cruising boat would be perfectly comfortable speaks volumes about how far we are from cruising performance cats, which is a loooong way.

The G4 sat in my ex-marina all last winter. To call it a cruising cat is laughable. It's a high-tech overnighter, at best. In truth, it probably capsized due to user error, not some fundamental flaw in the design, but that's beside the point.

It's all about weight. Cruisers carry weight. We're many years way from a foiling boat that can bridge the chasm between a performance concept machine to a usable cruising vessel, if ever.

[Bleemus]

The G4 capsized because the person on the mainsheet was asleep.

[valhalla360]

This is like saying I'm going to pull a travel trailer with a Ferrari because it has more HP than a 1 ton dually.

[SV DestinyAscen]

Foiling cats are definitely fast exciting and agile. But I don't see them being ocean cruisers or even ocean racers.

The margin of safety just isn't there. You'll get desk jockeys who say it's worth it - but good luck finding a sponsor event if the routine event requires constant rescue.

The benefit of two hulls isn't being used to provide stability. Foiling in the open ocean will be monohulls or trimarans imo.

They averaged 10 knots during the passage. Not slow but definitely not fast enough to risk life and limb. Spend money on a large trimarans and sweat less. Rich people aren't always dumb - money doesn't buy you a second life.

[robert sailor]

It's all a pipe dream as today's Cats would not even notice a difference if they had foils. Whether it's a mono or a Cat with foils the boat needs to be light in order to get up and boogie, that's not something you do with all the crap and weight the average cruiser has on the average cruising Cat.

[robert sailor]

Originally Posted by SV DestinyAscen

Foiling cats are definitely fast exciting and agile. But I don't see them being ocean cruisers or even ocean racers.

The margin of safety just isn't there. The benefit of two hulls isn't being used to provide stability. Foiling in the open ocean will be monohulls or trimarans imo.

They averaged 10 knots during the passage. Not slow but definitely not fast enough to risk life and limb. Spend money on a large trimarans and sweat less.

Some of the foiling mono hulls are averaging close to 20 knots in normal trade wind conditions in the current RTW race.

[Polux]

Foiling offshore cats , except the G4, are a rarity. All efforts seem to go to big racing trimarans that have a huge stability. Many of them, at least the more modern, are changing foils for flying ones ones.

Posted about that on my blog with videos at 6 months or so.

Have a look at one of the last that went for flying foils. A pity that on the last Middle sea race they were forced to race with conventional foils. It would be very interesting to see the duel with the other big trimaran with conventional foils.

https://www.youtube.com/watch?v=1i5H_Q1e2uI

[tms]

I thought this post was in response to what happened this week.

https://www.youtube.com/watch?v=6-DXEzfPaxU

[Cottontop]

Is an F1 family sedan the next logical step?

[Seaslug Caravan]

Beautifully engineered, beautifully built, superbly crewed by a cast of great sailors, but not an offshore boat in any respect.

A publicity stunt.

Geeze they've sailed a hobie 18 across the atlantic. SO WHAT

[donradcliffe]

Great video! I can't agree with Spithill that the oceans are going to cluttered with foiling cats in the future. The shots of the F4 in New York harbor show the instability in pitch, even in calm waters, which is the Achilles heel of the foiling cats offshore. It will be really interesting to watch the next generation AC boats to see if their pitch control systems have improved.

[SV DestinyAscen]

Originally Posted by donradcliffe

Great video! I can't agree with Spithill that the oceans are going to cluttered with foiling cats in the future. The shots of the F4 in New York harbor show the instability in pitch, even in calm waters, which is the Achilles heel of the foiling cats offshore. It will be really interesting to watch the next generation AC boats to see if their pitch control systems have improved.

Current AC 50 class box rules prevent dagger boards angle/shape from being adjusted during racing - and the adjustments can only be made by the mechanism that connects the daggerboard/foil to the hull.

The foils are also mandated to be L shaped - and unfortunately that inherent instability intended for racing is being copied by the industry trying to piggyback off the PR.

They would be so much better served studying the Moth foils - which are T shaped and have elevators - which are adjusted to keep the boat level relative to the water. But alas - we are where we are.