11 ms·

Hydrofoiling

131 points by AndrewDucker 5y ago

Gravityloss 5y ago
Another solution that increases efficiency is to travel slower and design the hull for that. Non planing boats look like sailboats or retro motorboats. Most boat owners can't afford a hydroplaning boat.
- deleted 5y ago
  [deleted]
- usrusr 5y ago
  Isn't that a bit of a tautology? Most boat owners can't afford a boat. (Talking about recreational of course)
  - Gravityloss 5y ago
    No. Hydroplaning boats cost multiples of regular boats. Three kinds. Regular planing boat. Cheap and fast but very inefficient and thus can't be electric. Hydroplaning boat. Fast, efficient so can be made electric. But very expensive. Non planing boat. Cheap, efficient. Can be made electric. But is slow.
- hnzix 5y ago
  TFA cites speed as a constraining factor for their particular needs: "attractive for the “tugboat” flavor of pleasure boats. Which is perfectly OK unless you want to cover some distance and get there fast."
- ansible 5y ago
  A sailboat is the original "carbon free" way of propulsion for boats and ships. No, it is not as fast as a hydrofoil, but it also won't run out of power except under rare weather conditions (utterly becalmed). Not that boats don't do a lot of environmental damage in other ways. Bilge tanks, anti-fouling paint flaking off, etc.
  - sesuximo 5y ago
    Anti fouling is the only thing I can think of that’s really bad about boats. The rest seems ok/not worse than living on land.
sethbannon 5y ago
There's a YC company that's building hydrofoil container ships to lower the GHG emissions from shipping. https://www.boundarylayer.tech/ https://www.boundarylayer.tech/
- unwind 5y ago
  Hadn't seen those, really interesting, thanks! Also can't help smiling at their use of "BLT" as an abbreviation for the company name, I guess we know what their Official Company Lunch is going to be [1]. :) I wonder if there has been any progress, the site is kind of ... light on the details. The prototype single-container ship was cute, though. [1]: https://en.wikipedia.org/wiki/BLT https://en.wikipedia.org/wiki/BLT
- raverbashing 5y ago
  Interesting, and the video is informative (though a bit short) but we always want to know the caveats - Why hasn't this been built before? Yes, minor hydrofoil ships have been built but why not cargo ones? (Constructor conservatism? Some issues that others have run into? Lack of technology before that) - How does this fare in a marine thunderstorm? - How many customers are time sensitive (but not much) so as to fit their window? - What kind of problems can going 4x the speed on an open ocean can create? - Is the actual cost 4x less once you factor everything in? My bet is that this makes sense for shorter routes (like multiple ferry routes in Europe), maaaybe for "shorter" cargo routes, not so sure for the longer routes (though China-LA is not "too long")
  - nicoburns 5y ago
    > Yes, minor hydrofoil ships have been built but why not cargo ones? I'm assuming that the additional of the weight of the cargo means that you would need to go much faster in order to lift the ship up on the hydrofoils, and this makes it infeasable.
    - imglorp 5y ago
      Also you need to lift your fuel and you might get into a rocket equation type problem. Fuel is less dense than water so one might imagine it contributes a little to buoyancy but aloft, you're paying to lift it along with the cargo. Fuel means range so that all might get back to the mission: ferry or transoceanic.
sails 5y ago
Hydrofoiling seems to be having something of a grassroots style renaissance, with incredible interest across all of boating, sailing, windsurfing, kitesurfing, surfing and pretty much any other board/boat water sport. I find this peculiar because hydrofoils were seemingly much more common in the 80-90's in industrial applications such as ferries, but now suddenly have become hugely popular in recreational space, and rapid innovation in the design and construction of foils across all of the domains. Very interesting if you are interested in boats and water sports.
- ako 5y ago
  Maybe carbon fiber technology has improved and has become more affordable? I'm in the proces of learning to use a kitesurf hydrofoil, it's funny to see the gps tracks from a smartwatch on strava, very messy, like a child scribbling.
- usrusr 5y ago
  The 1980ies did not have foil sailing which is just incredibly inspiring. And that in turn is most likely enabled by carbon fiber manufacturing having become somewhat mainstream (and much better), even if it may not be entirely impossible to do in steel. Also, for industrial applications (and for recreational without self-imposed restrictions), high frequency automated active servo control is now very much in the realm of practicality. Back then it was all self-stabilizing, which led to some very bumpy rides.
  - seryoiupfurds 5y ago
    Well, there was the Hobie Trifoiler. http://trifoiler.info/media/index.php?title=Main_Page http://trifoiler.info/media/index.php?title=Main_Page https://www.youtube.com/watch?v=zXSgZCDVWOM https://www.youtube.com/watch?v=zXSgZCDVWOM I don't know if modern consumer-level designs are sophisticated enough to be using much CFD, but it definitely seems like the easy availability of CAD should be playing a role.
- JJMalina 5y ago
  Foiling has made it possible to do all of these sports with less power. I can now go windsurfing in 12kts on the same size sail that I would use for 20kts. I remember seeing foils in the late 90s and early 2000s but they weren't available to purchase. I wonder why. Maybe it's because the construction process hadn't been commercialized yet.
londons_explore 5y ago
Am I correct in saying the key difficulty of a hydrofoil is making sure the boat never gets too high (and the hydrofoil leaving the water, causing massive mechanical stresses on the supports and failure) or too low (and the boat slamming into a wave at high speed, causing a very sudden stop and injured passengers)?
- SahAssar 5y ago
  This is explained on wikipedia: https://en.wikipedia.org/wiki/Hydrofoil#Foil_configurations https://en.wikipedia.org/wiki/Hydrofoil#Foil_configurations Basically, yes, for fully submerged hydrofoils you need to make sure you don't get too high or low. For surface-piercing you don't, they self-stabilize.
- Candelaboat 5y ago
  Mikael at Candela, the hydrofoil boat maker, here. Yes, that's a key difficulty that has to be solved by using sensors that detect flight height, and distance to the waves, among other things. If the foil leaves the water, you ventilate and come down. We use a flight controller, a kind of computer, to perform these calculations. Some sailing boats have wands, ie a mechanical stick that detects waves in front of the boat,, but using ultrasonic sensors and adjustable hydrofoils is a way more accurate solution. Check us out here: candela.com
nixy 5y ago
Candela will also provide boats for a trial with the Stockholm Public Transport system, which currently employs quite a few traditional boats for transport around the city. https://www.mynewsdesk.com/candela-speedboat-ab/pressreleases/stockholm-testar-vaerldens-snabbaste-elektriska-passagerarfartyg-candela-p-30-3085063 https://www.mynewsdesk.com/candela-speedboat-ab/pressrelease... https://candelaspeedboat.com/public-transport/ https://candelaspeedboat.com/public-transport/
gnopgnip 5y ago
For a cruiser a hybrid electric system has a lot of benefits. Basically it uses the conventional diesel engine, prop, gearbox, and adds an electric motor that bolts on. So if something goes wrong, all of those parts can be serviced worldwide. The electric motor is a form of redundancy, and can also be used as a starter if the starter fails, and the diesel motor can function even if the electric motor fails. At low speeds the electric motor only is used. The electric can be used at the same time for some extra power. For short trips with shore power you can get around without using any fuel. And you can recharge while cruising with the electric motor working as an alternator, allowing you to spend most of the time on only electric, extending your range.
- dzhiurgis 5y ago
  Some boats charge batteries via shaft while on sail. Otherwise diesel generators aren't mechanically connected. What I do wonder is whether automotive range extenders can be retrofitted instead of marine gensets. Seems way cheaper.
dzhiurgis 5y ago
Charging these by marinas with solar shade seems obvious fit - it protects the boat from weather plus their batteries can balance grid as they are only used like 0.01% of time. Question I have - do hydrofoils use ground effect to generate extra lift?
- barbegal 5y ago
  Water is considerably different to air and there is no analogous effect for ground effect in water. Edit: I realise now that you mean hydrofoil as in the boat rather than the submerged wing (it's confusing that they both have the same name). I don't think the ground effect from the boat's hull contributes much to the lift but it is something that the designers of the AC75 boats take into consideration https://www.sailmagazine.com/racing/36th-americas-cup-different-design-approaches https://www.sailmagazine.com/racing/36th-americas-cup-differ...
  - nixy 5y ago
    I think the OP is referring to ground effect above the water surface, as employed by for example eraknoplans (https://en.wikipedia.org/wiki/Lun-class_ekranoplan https://en.wikipedia.org/wiki/Lun-class_ekranoplan)
    - jojohohanon 5y ago
      I would speculate no, as it seems a trade off between inherently stable and inefficient (standard v shaped hull) and inherently unstable, but more efficient (inverted v). Ekranoplans have wings and aerodynamic control surfaces. I also wonder (this may be the primary reason) if the speeds a hydroplane achieves are sufficient to generate much lift in air from something the size of a boat hull.
- sesuximo 5y ago
  I’m guessing no because you have to travel pretty fast for an air wing to have an effect (~50-200mph), but you travel relatively slower for the hydrofoil to perform well (10-30mph). (These are very approximate numbers I made up from experience riding on different types of boats. They are not physical limits or anything like that!)
mrfusion 5y ago
So why aren’t hydrofoils used almost everywhere? Who wouldn’t want less drag?
- jpm_sd 5y ago
  Big waves and high winds will cause your vessel to go unstable and crash. Ocean-crossing cargo vessels have to handle all weather conditions. Hydrofoils significantly increase draft and nobody wants to dredge their ports and canals 20 feet deeper. Also drag is proportional to velocity squared, so you can save a ton of fuel just by slowing down a bit. Much easier than designing a hydrofoil cargo ship.
  - nradov 5y ago
    Many hydrofoil designs are retractable so in ports they don't draw much more water than a conventional displacement hull. Agreed on the other points.
    - SigmundA 5y ago
      Only if you remember to retract them.
- Candelaboat 5y ago
  Mikael at Candela here. Because it's super hard to make the control system for an inherently unstable boat. It took five years of R&D to make it work in all manners of situations, banked turns etc. Conventional boat builders don't have access to software and control systems engineers, and tech companies seldom invest in the marien sector. But once we got it working, there are no real drawbacks, only benefits. Smooth, quiet, and fun to drive. Check out candela.com for more videos.
- breck 5y ago
  This is anecdotal but in the past ~5 years I've noticed foils popping up in more and more places (in Oahu).
- SigmundA 5y ago
krupan 5y ago
Skiing or wakeboarding behind this would be pretty rough except on really smooth water. What else do people use a little boat like this for?
- jrwoodruff 5y ago
  I don't think you -could- wakeboard behind this, right? The whole point of wakeboard boats is to displace as much water as possible in a controlled way. Skiing would be interesting though.
  - krupan 5y ago
    You could wakeboard, it would just be kinda boring without the wake :-)
- Candelaboat 5y ago
  Waterskiing behind a Candela C-7 here: https://www.youtube.com/watch?v=pAMlAcSEI1I&t=10s https://www.youtube.com/watch?v=pAMlAcSEI1I&t=10s
rmac 5y ago
Has anyone seen hybrid propeller / jet-pump boats or foils? It seems like it would make sense to have a gas engine and propeller to get the foil on-plane from stopped, then when "gliding" switch to a battery powered jet pump to keep it at speed.
pp19dd 5y ago
Engine lost compression in two cylinders on my 5.7 GL Volvo Penta. ~ 300 HP, leaky exhaust riser. Took the opportunity to look into an electric option that can bring a 4,700 lb boat on plane, comparable power that is in production and available. - Evoy hurricane inboard, 600 kW: NOK 1.497.000 - Battery pack: medium range, 252 kWh: NOK 1.476.000 In US dollars, that's $360,000 and I'd have to ship it from Norway. Closest second option was about half that price using BMW i3 batteries, at half power. Meanwhile, a new marine engine was $10,000 by comparison, or to repair exhaust and rebuild to last another 17 years, $5,000. Boating is a luxury and I can't excuse it in environmental terms, same as I can't excuse electing not to walk 2 hours to my local starbucks for a consistent grande pike I enjoy in favor of brewing my own. But marine electric is currently nowhere near being a practical solution, and you cannot hydrofoil in all boating conditions, especially in choppy waters, or where there are seasonal floating obstructions. Boats do have notoriously small efficiencies (1-4 mpg) in both displacement and planing modes, but consider that for an automobile to have its 25 mpg average we pour approximately 124,000 gallons of crude oil per mile every 5-10 years for a two lane asphalt road, a coarse byproduct of refined petroleum. My whole point here is not to equivocate in any terms, but that it's easy to overlook externalized costs. Moving an object anywhere is a difficult problem.
- acdha 5y ago
  Is biodiesel getting much interest in boating? Given the cost disparities I wonder whether it’d make more sense to explore emissions controls with a non-fossil fuel until a better battery technology emerges.
  - bosswipe 5y ago
    If the goAl is reduction of emissions or generic environment friendliness biodiesel is not a solution. Especially if the biodiesel comes from palm oil.
    - acdha 5y ago
      It very much depends on the source - palm oil is a disaster but if there are alternatives it seems like it would be a net win for CO2 if you could avoid additional fossil fuel extraction. I’m thinking of a guy I knew who used to process oil from a local restaurant’s deep fryer – that would be problematic getting the formulation right for an advanced car engine but my (possibly completely incorrect) understanding is that marine Diesel engines are a lot simpler and there isn’t an obvious path for short-term replacement the way there is for an EV.
uncoder0 5y ago
Sailing has pushed Hydrofoiling to the next level there are 100m boats coming out that claim to be able to do 2.2x wind speed downwind. One of the things I miss the most living in Central Texas is sailing on trapeze and foiling. If I were back near the coast I'd buy one of these: https://iflysail.com/ https://iflysail.com/
w_t_payne 5y ago
My friends also have this electric propulsion startup:- https://www.radpropulsion.com/ https://www.radpropulsion.com/
korse 5y ago
I take it the author hasn't heard of E-Foils or jetfoils? Maybe not a family transport option, but we're talking a surfboard filled with 18650 cells (or similar) riding on a underwater wing driven by a jet or small propeller. They are relatively old with companies building competition models at least five years ago. The technology at heart is an outgrowth of the portable electric vehicle industry and hydrofoil development in the windsurfing commnity. If you think this article is neat, I would check out the technology. You can build a performance board yourself for sub 3 grand US (possibly less if you are willing to vacuum mold the board yourself). Good resources are available from the portable electric vehicle or electric skateboard communities. Board building has been covered in depth by generations of surfers.
kbenson 5y ago
The Candela boats he links to were discussed here[1] a while back, in case anyone is interested in that discussion. 1: https://news.ycombinator.com/item?id=24222208 https://news.ycombinator.com/item?id=24222208
jeffreyrogers 5y ago
> The core ideas behind the Candela C-7 aren’t that complicated: Electric powertrain, battery, hydrofoils, software trim control. I enjoyed the article, so I'm not trying to pick on the author too much, but I always find it funny when technical people say this about engineered things. Each of those things is literally an entire discipline and you could still spend a career (or at least many years) only working on one of them. I think we have a tendency to think that because we can understand something and have taken some of the magic out of it that it isn't complex.
sunstone 5y ago
The obvious solution here is the world's first green transportation, a regular old sail boat.

131 points by AndrewDucker 5y ago

Another solution that increases efficiency is to travel slower and design the hull for that. Non planing boats look like sailboats or retro motorboats. Most boat owners can't afford a hydroplaning boat.

deleted 5y ago
[deleted]
usrusr 5y ago
Isn't that a bit of a tautology? Most boat owners can't afford a boat. (Talking about recreational of course)
- Gravityloss 5y ago
  No. Hydroplaning boats cost multiples of regular boats. Three kinds. Regular planing boat. Cheap and fast but very inefficient and thus can't be electric. Hydroplaning boat. Fast, efficient so can be made electric. But very expensive. Non planing boat. Cheap, efficient. Can be made electric. But is slow.
hnzix 5y ago
TFA cites speed as a constraining factor for their particular needs: "attractive for the “tugboat” flavor of pleasure boats. Which is perfectly OK unless you want to cover some distance and get there fast."
ansible 5y ago
A sailboat is the original "carbon free" way of propulsion for boats and ships. No, it is not as fast as a hydrofoil, but it also won't run out of power except under rare weather conditions (utterly becalmed). Not that boats don't do a lot of environmental damage in other ways. Bilge tanks, anti-fouling paint flaking off, etc.
- sesuximo 5y ago
  Anti fouling is the only thing I can think of that’s really bad about boats. The rest seems ok/not worse than living on land.

sethbannon 5y ago

There's a YC company that's building hydrofoil container ships to lower the GHG emissions from shipping. https://www.boundarylayer.tech/ https://www.boundarylayer.tech/

unwind 5y ago
Hadn't seen those, really interesting, thanks! Also can't help smiling at their use of "BLT" as an abbreviation for the company name, I guess we know what their Official Company Lunch is going to be [1]. :) I wonder if there has been any progress, the site is kind of ... light on the details. The prototype single-container ship was cute, though. [1]: https://en.wikipedia.org/wiki/BLT https://en.wikipedia.org/wiki/BLT
raverbashing 5y ago
Interesting, and the video is informative (though a bit short) but we always want to know the caveats - Why hasn't this been built before? Yes, minor hydrofoil ships have been built but why not cargo ones? (Constructor conservatism? Some issues that others have run into? Lack of technology before that) - How does this fare in a marine thunderstorm? - How many customers are time sensitive (but not much) so as to fit their window? - What kind of problems can going 4x the speed on an open ocean can create? - Is the actual cost 4x less once you factor everything in? My bet is that this makes sense for shorter routes (like multiple ferry routes in Europe), maaaybe for "shorter" cargo routes, not so sure for the longer routes (though China-LA is not "too long")
- nicoburns 5y ago
  > Yes, minor hydrofoil ships have been built but why not cargo ones? I'm assuming that the additional of the weight of the cargo means that you would need to go much faster in order to lift the ship up on the hydrofoils, and this makes it infeasable.
  - imglorp 5y ago
    Also you need to lift your fuel and you might get into a rocket equation type problem. Fuel is less dense than water so one might imagine it contributes a little to buoyancy but aloft, you're paying to lift it along with the cargo. Fuel means range so that all might get back to the mission: ferry or transoceanic.

sails 5y ago

Hydrofoiling seems to be having something of a grassroots style renaissance, with incredible interest across all of boating, sailing, windsurfing, kitesurfing, surfing and pretty much any other board/boat water sport. I find this peculiar because hydrofoils were seemingly much more common in the 80-90's in industrial applications such as ferries, but now suddenly have become hugely popular in recreational space, and rapid innovation in the design and construction of foils across all of the domains. Very interesting if you are interested in boats and water sports.

ako 5y ago
Maybe carbon fiber technology has improved and has become more affordable? I'm in the proces of learning to use a kitesurf hydrofoil, it's funny to see the gps tracks from a smartwatch on strava, very messy, like a child scribbling.
usrusr 5y ago
The 1980ies did not have foil sailing which is just incredibly inspiring. And that in turn is most likely enabled by carbon fiber manufacturing having become somewhat mainstream (and much better), even if it may not be entirely impossible to do in steel. Also, for industrial applications (and for recreational without self-imposed restrictions), high frequency automated active servo control is now very much in the realm of practicality. Back then it was all self-stabilizing, which led to some very bumpy rides.
- seryoiupfurds 5y ago
  Well, there was the Hobie Trifoiler. http://trifoiler.info/media/index.php?title=Main_Page http://trifoiler.info/media/index.php?title=Main_Page https://www.youtube.com/watch?v=zXSgZCDVWOM https://www.youtube.com/watch?v=zXSgZCDVWOM I don't know if modern consumer-level designs are sophisticated enough to be using much CFD, but it definitely seems like the easy availability of CAD should be playing a role.
JJMalina 5y ago
Foiling has made it possible to do all of these sports with less power. I can now go windsurfing in 12kts on the same size sail that I would use for 20kts. I remember seeing foils in the late 90s and early 2000s but they weren't available to purchase. I wonder why. Maybe it's because the construction process hadn't been commercialized yet.

londons_explore 5y ago

Am I correct in saying the key difficulty of a hydrofoil is making sure the boat never gets too high (and the hydrofoil leaving the water, causing massive mechanical stresses on the supports and failure) or too low (and the boat slamming into a wave at high speed, causing a very sudden stop and injured passengers)?

SahAssar 5y ago
This is explained on wikipedia: https://en.wikipedia.org/wiki/Hydrofoil#Foil_configurations https://en.wikipedia.org/wiki/Hydrofoil#Foil_configurations Basically, yes, for fully submerged hydrofoils you need to make sure you don't get too high or low. For surface-piercing you don't, they self-stabilize.
Candelaboat 5y ago
Mikael at Candela, the hydrofoil boat maker, here. Yes, that's a key difficulty that has to be solved by using sensors that detect flight height, and distance to the waves, among other things. If the foil leaves the water, you ventilate and come down. We use a flight controller, a kind of computer, to perform these calculations. Some sailing boats have wands, ie a mechanical stick that detects waves in front of the boat,, but using ultrasonic sensors and adjustable hydrofoils is a way more accurate solution. Check us out here: candela.com

nixy 5y ago

Candela will also provide boats for a trial with the Stockholm Public Transport system, which currently employs quite a few traditional boats for transport around the city. https://www.mynewsdesk.com/candela-speedboat-ab/pressreleases/stockholm-testar-vaerldens-snabbaste-elektriska-passagerarfartyg-candela-p-30-3085063 https://www.mynewsdesk.com/candela-speedboat-ab/pressrelease... https://candelaspeedboat.com/public-transport/ https://candelaspeedboat.com/public-transport/

gnopgnip 5y ago

For a cruiser a hybrid electric system has a lot of benefits. Basically it uses the conventional diesel engine, prop, gearbox, and adds an electric motor that bolts on. So if something goes wrong, all of those parts can be serviced worldwide. The electric motor is a form of redundancy, and can also be used as a starter if the starter fails, and the diesel motor can function even if the electric motor fails. At low speeds the electric motor only is used. The electric can be used at the same time for some extra power. For short trips with shore power you can get around without using any fuel. And you can recharge while cruising with the electric motor working as an alternator, allowing you to spend most of the time on only electric, extending your range.

dzhiurgis 5y ago
Some boats charge batteries via shaft while on sail. Otherwise diesel generators aren't mechanically connected. What I do wonder is whether automotive range extenders can be retrofitted instead of marine gensets. Seems way cheaper.

dzhiurgis 5y ago

Charging these by marinas with solar shade seems obvious fit - it protects the boat from weather plus their batteries can balance grid as they are only used like 0.01% of time. Question I have - do hydrofoils use ground effect to generate extra lift?

barbegal 5y ago
Water is considerably different to air and there is no analogous effect for ground effect in water. Edit: I realise now that you mean hydrofoil as in the boat rather than the submerged wing (it's confusing that they both have the same name). I don't think the ground effect from the boat's hull contributes much to the lift but it is something that the designers of the AC75 boats take into consideration https://www.sailmagazine.com/racing/36th-americas-cup-different-design-approaches https://www.sailmagazine.com/racing/36th-americas-cup-differ...
- nixy 5y ago
  I think the OP is referring to ground effect above the water surface, as employed by for example eraknoplans (https://en.wikipedia.org/wiki/Lun-class_ekranoplan https://en.wikipedia.org/wiki/Lun-class_ekranoplan)
  - jojohohanon 5y ago
    I would speculate no, as it seems a trade off between inherently stable and inefficient (standard v shaped hull) and inherently unstable, but more efficient (inverted v). Ekranoplans have wings and aerodynamic control surfaces. I also wonder (this may be the primary reason) if the speeds a hydroplane achieves are sufficient to generate much lift in air from something the size of a boat hull.
sesuximo 5y ago
I’m guessing no because you have to travel pretty fast for an air wing to have an effect (~50-200mph), but you travel relatively slower for the hydrofoil to perform well (10-30mph). (These are very approximate numbers I made up from experience riding on different types of boats. They are not physical limits or anything like that!)

mrfusion 5y ago

So why aren’t hydrofoils used almost everywhere? Who wouldn’t want less drag?

jpm_sd 5y ago
Big waves and high winds will cause your vessel to go unstable and crash. Ocean-crossing cargo vessels have to handle all weather conditions. Hydrofoils significantly increase draft and nobody wants to dredge their ports and canals 20 feet deeper. Also drag is proportional to velocity squared, so you can save a ton of fuel just by slowing down a bit. Much easier than designing a hydrofoil cargo ship.
- nradov 5y ago
  Many hydrofoil designs are retractable so in ports they don't draw much more water than a conventional displacement hull. Agreed on the other points.
  - SigmundA 5y ago
    Only if you remember to retract them.
Candelaboat 5y ago
Mikael at Candela here. Because it's super hard to make the control system for an inherently unstable boat. It took five years of R&D to make it work in all manners of situations, banked turns etc. Conventional boat builders don't have access to software and control systems engineers, and tech companies seldom invest in the marien sector. But once we got it working, there are no real drawbacks, only benefits. Smooth, quiet, and fun to drive. Check out candela.com for more videos.
breck 5y ago
This is anecdotal but in the past ~5 years I've noticed foils popping up in more and more places (in Oahu).
SigmundA 5y ago

krupan 5y ago

Skiing or wakeboarding behind this would be pretty rough except on really smooth water. What else do people use a little boat like this for?

jrwoodruff 5y ago
I don't think you -could- wakeboard behind this, right? The whole point of wakeboard boats is to displace as much water as possible in a controlled way. Skiing would be interesting though.
- krupan 5y ago
  You could wakeboard, it would just be kinda boring without the wake :-)
Candelaboat 5y ago
Waterskiing behind a Candela C-7 here: https://www.youtube.com/watch?v=pAMlAcSEI1I&t=10s https://www.youtube.com/watch?v=pAMlAcSEI1I&t=10s

rmac 5y ago

Has anyone seen hybrid propeller / jet-pump boats or foils? It seems like it would make sense to have a gas engine and propeller to get the foil on-plane from stopped, then when "gliding" switch to a battery powered jet pump to keep it at speed.

pp19dd 5y ago

Engine lost compression in two cylinders on my 5.7 GL Volvo Penta. ~ 300 HP, leaky exhaust riser. Took the opportunity to look into an electric option that can bring a 4,700 lb boat on plane, comparable power that is in production and available. - Evoy hurricane inboard, 600 kW: NOK 1.497.000 - Battery pack: medium range, 252 kWh: NOK 1.476.000 In US dollars, that's $360,000 and I'd have to ship it from Norway. Closest second option was about half that price using BMW i3 batteries, at half power. Meanwhile, a new marine engine was $10,000 by comparison, or to repair exhaust and rebuild to last another 17 years, $5,000. Boating is a luxury and I can't excuse it in environmental terms, same as I can't excuse electing not to walk 2 hours to my local starbucks for a consistent grande pike I enjoy in favor of brewing my own. But marine electric is currently nowhere near being a practical solution, and you cannot hydrofoil in all boating conditions, especially in choppy waters, or where there are seasonal floating obstructions. Boats do have notoriously small efficiencies (1-4 mpg) in both displacement and planing modes, but consider that for an automobile to have its 25 mpg average we pour approximately 124,000 gallons of crude oil per mile every 5-10 years for a two lane asphalt road, a coarse byproduct of refined petroleum. My whole point here is not to equivocate in any terms, but that it's easy to overlook externalized costs. Moving an object anywhere is a difficult problem.

acdha 5y ago
Is biodiesel getting much interest in boating? Given the cost disparities I wonder whether it’d make more sense to explore emissions controls with a non-fossil fuel until a better battery technology emerges.
- bosswipe 5y ago
  If the goAl is reduction of emissions or generic environment friendliness biodiesel is not a solution. Especially if the biodiesel comes from palm oil.
  - acdha 5y ago
    It very much depends on the source - palm oil is a disaster but if there are alternatives it seems like it would be a net win for CO2 if you could avoid additional fossil fuel extraction. I’m thinking of a guy I knew who used to process oil from a local restaurant’s deep fryer – that would be problematic getting the formulation right for an advanced car engine but my (possibly completely incorrect) understanding is that marine Diesel engines are a lot simpler and there isn’t an obvious path for short-term replacement the way there is for an EV.

uncoder0 5y ago

Sailing has pushed Hydrofoiling to the next level there are 100m boats coming out that claim to be able to do 2.2x wind speed downwind. One of the things I miss the most living in Central Texas is sailing on trapeze and foiling. If I were back near the coast I'd buy one of these: https://iflysail.com/ https://iflysail.com/

w_t_payne 5y ago

My friends also have this electric propulsion startup:- https://www.radpropulsion.com/ https://www.radpropulsion.com/

korse 5y ago

I take it the author hasn't heard of E-Foils or jetfoils? Maybe not a family transport option, but we're talking a surfboard filled with 18650 cells (or similar) riding on a underwater wing driven by a jet or small propeller. They are relatively old with companies building competition models at least five years ago. The technology at heart is an outgrowth of the portable electric vehicle industry and hydrofoil development in the windsurfing commnity. If you think this article is neat, I would check out the technology. You can build a performance board yourself for sub 3 grand US (possibly less if you are willing to vacuum mold the board yourself). Good resources are available from the portable electric vehicle or electric skateboard communities. Board building has been covered in depth by generations of surfers.

kbenson 5y ago

The Candela boats he links to were discussed here[1] a while back, in case anyone is interested in that discussion. 1: https://news.ycombinator.com/item?id=24222208 https://news.ycombinator.com/item?id=24222208

jeffreyrogers 5y ago

> The core ideas behind the Candela C-7 aren’t that complicated: Electric powertrain, battery, hydrofoils, software trim control. I enjoyed the article, so I'm not trying to pick on the author too much, but I always find it funny when technical people say this about engineered things. Each of those things is literally an entire discipline and you could still spend a career (or at least many years) only working on one of them. I think we have a tendency to think that because we can understand something and have taken some of the magic out of it that it isn't complex.

sunstone 5y ago

The obvious solution here is the world's first green transportation, a regular old sail boat.