Foiling power boats

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darkside

Senior Member
Joined
Apr 4, 2016
Messages
412
Location
New Zealand
Vessel Name
Ahi
Vessel Make
Roger Hill Powercat
I wonder how long before we see cruising pleasure boats in the doing this. A lot of power to get the lift, after that I assume quite efficient. Screenshot_20230902_135802_Gallery.jpg
 
Greetings,
Mr.d. I think both the US and Canadian military tested prototype hydrofoils many moons ago. Neither panned out IIRC.


So IF the military with tons of $$ can't make a go of it, I doubt recreational manufacturers will even try.
 
Greetings,
Mr.d. I think both the US and Canadian military tested prototype hydrofoils many moons ago. Neither panned out IIRC.


So IF the military with tons of $$ can't make a go of it, I doubt recreational manufacturers will even try.


U.S. built six which actually served for about 15 years. At least one participated in the invasion of Grenada.
 

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Here's all of them, on the way to the scrapyard in 1993:
 

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I think the difference now is computers controlled foils rather than fixed foils of the past.
A huge gain in efficiency if the foils can be adjusted to match boat speed and sea conditions.
The latest AC40s only have three crew, the foils can look after themselves.
 
So IF the military with tons of $$ can't make a go of it, I doubt recreational manufacturers will even try.

The military probably has design requirements like hull thickness and impact resistance that a recreational boat wouldn't have. That might make for enough of a weight penalty for the navy ships not to be feasible, but recreationally it might work.

The America's Cup boats are using them now. In the automotive world it takes a while for technology developed for racing to make its way to the average consumer. I'm hoping it will be the same for foiling boats.
 
Ran across this the other day. Thought the most interesting part is the reduction in power requirements when foiling. It sort of seems that it'd make longer range solar power propulsion actually doable. It's certainly not a trawler so this isn't likely the best forum but it makes as much sense as showing a bunch of military stuff.
 
I looked at a Candela runabout last summer. Pretty much everything was carbon fiber. It's interesting to watch along with the electrification of pleasure boats.

I've seen a number of electric foiling surfboards recently. And there are a bunch of foiling sailboats. Clearly it's here to stay this time.
 
Good summary of pros and cons.
https://www.boatblurb.com/post/hydrofoils-are-back-let-s-weigh-the-pros-and-cons

As an engineer the reduced wetted surface and thus lower drag is pretty self evident. However in the real world things aren't that simple. For specific applications they are great but don't have the all around capability and versatility of a conventional hull. While computer controls make them more easy to control keep in mind this is an electronic system in salt water, a recipe for problems. So they'll probably stay what they've always been: a rich mans toy or a special purpose government vessel. They are a blast though, I've been on the HK to Macao Boeing foil multiple times, it's impressive. The Russian ones are a bit less so.
 
Foils are fairly common on trawler catamarans in the recreational space to reduce wetted surface and increase efficiency. We chose not to avoid the extra risk.
Some time ago on a delivery we picked up a small branch on a foil on a 20m cat. No amount of backing down would free it so I had to dive it to get it off.
I am a big fan of foils in other applications 113.jpg
 
Foils are fairly common on trawler catamarans in the recreational space to reduce wetted surface and increase efficiency.

Not common around here! Can you point to examples?

We may be stretching the trawler label a little thin here [emoji3]
 
Ran across this the other day. Thought the most interesting part is the reduction in power requirements when foiling. It sort of seems that it'd make longer range solar power propulsion actually doable. It's certainly not a trawler so this isn't likely the best forum but it makes as much sense as showing a bunch of military stuff.

no thanks on the boat but i do need a new captain.
 
Not common around here! Can you point to examples?
Too many to list but Roger Hill, Nick de Waal, McConaghy, Aquila and Bladerunner spring to mind.
Google foil assisted catamarans.
 
I did that. Interesting stuff.

NZ seems to be leading the charge. No surprise I guess, given the AC history and the vast open water distances.
 
Ran across this the other day. Thought the most interesting part is the reduction in power requirements when foiling. It sort of seems that it'd make longer range solar power propulsion actually doable. It's certainly not a trawler so this isn't likely the best forum but it makes as much sense as showing a bunch of military stuff.
illiant.



Absolutely fascinating. Absolutely brilliant. Of course I want one. Bimini in 40 minutes, Middle Grounds in an hour and a half for pennies in fuel + the hardware cost which no mention of anywhere.
 
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Clearly a leap forward from the early foiling recreational boats. The first I'm aware of was a flying Bayliner that first flew in 1992, then some time later with the electronic height sensor.

The Navier boats may work well as day boats or marina hoppers in a well supported area where charging every night is possible. It won't work well for the areas some of us who cruise more remote waters. BC, Ak for example where marinas are few and far between. And those facilities have limited electrical power.

The boat demonstrated cruises at 20 kts with a 75 nm range. So, 3.75 hrs generating 30 HP. Those who are better at electrical engineering than I can calculate charge time at 110 V, 30 APMs

Another issue for remote cruising is the lack of living space and ability to carry all that is needed and wanted for a comfortable life at anchor for a week or two at a time. To do that we'd need to have a generator, fuel tanks and fuel aboard.

Navier has made progress but they still have a long way to go to create a good remote area cruising boat.

For those of us uncomfortable with electronically controlled engines in the marine environment this entire boat is highly dependent upon electronics.

You mentioned hardware costs. Is that the cost of the boat? $650,000 for the version demonstrated.
illiant.


Absolutely fascinating. Absolutely brilliant. Of course I want one. Bimini in 40 minutes, Middle Grounds in an hour and a half for pennies in fuel + the hardware cost which no mention of anywhere.
 
................................You mentioned hardware costs. Is that the cost of the boat? $650,000 for the version demonstrated.


Have no idea of the price tag but would not be surprised at $650K. I just ran across a fishing charter Hub Marine out of Madera Beach on the GOM. They have a foil Cat. 2 hours to the Middle Grounds. Fish, fish fish. 2 hours home in time for 5 o'clock somewhere. $399
 
We have the hysucat foils (designed by Hoppe) on a 46 powercat that do not protrude below the hull bottom—beefy reverse stainless chevron midship and an adjustable stainless foil aft that compensates for longitudinal center of gravity. The adjustment is really a set it and forget it ordeal unless there is an abnormal load plan. Ours produce about a 12-18” lift which take 25%+ of the wetted surface out of the drag equation at cruise speeds. Efficiency gains are realized at anything above forward idle. Maintenance of this variety is a non-issue.

Some of the designs in the prior posts seem to have foils protruding below wetted surfaces but the design goals of those appear to take the hull completely out of the water—and require a propulsion system that may be somewhat complex.
 
Hemi, sounds like you have a foil assisted cat? That makes a lot more sense to me than a flying hydrofoil.
 
Correct. The 46 is foil assisted and the wings span the hulls. My experience with catamarans is limited to only this powercat and I acquired after the prior owner spent untold $$$ to commission the design, manufacturing and install. I am thankful for the prior investment because I benefit from a low maintenance improvement to efficiency that just plain works.
 
Surprised no one has posted this. They are a competitor to Candela. Very interesting story about the CEO and her journey to build this company.

https://www.navierboat.com/

A potential issue when I read a review by someone using one in Boston Harbor is that in many areas where there is say a 5kt speed limit, the boat doesn't foil and therefore doesn't get the advantage of low drag/wetted surface. All electric boat needs every advantage it can get to extend battery life.

Says 75 mi at 30kts, 30' boat starts at 300k for open model up to 450k for the cabin version. I would think it should have both solar and wind regen while it is cruising or at dock.
 
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