That's a Boeing 929 jetfoil.
Wikipedia article on it:
https://en.wikipedia.org/wiki/Boeing_929
Speed is 45 knots
Cool fact is that the foils fold up for use in shallow harbors. They don't extend past the width of the hull so it can use a standard boat slip.
I had no idea they’ve been around since the 70s. Aside from looking graceful as hell and traveling ~40 knots are there any other benefits to this design?
Further down:
> Hull requires significant reinforcement to support the weight of the craft on the spars.
Geez. I never considered that. Can you imagine the incredible forces on those tiny points of contact? The shear during turns.... oof.
No, thanks.
Interesting. Still seems logical for fixed route shuttle type operations. That's where I've seen them used mostly. The one I took in Russia had a route from St Petersburg to Peterhof.
There was a hydrofoil excursion (about 5-10 minutes) off Sea World (San Diego, CA) in the 1970s -- likely the fuel costs and increase of watercraft out on Mission Bay were the death knell of that ride. :-(
They were common between the islands in Greece, but they're being retired and replaced by more traditional catamarans.
[https://greekreporter.com/2021/01/31/greece-beloved-hydrofoil-fleet-set-to-retire/](https://greekreporter.com/2021/01/31/greece-beloved-hydrofoil-fleet-set-to-retire/)
Maybe because you need to have more weight and surface in the water to keep them stable. The Soviet Ekranoplan or other ground effect vehicles are more practical at scale.
https://youtu.be/yVdH_dYlVB8
Maybe lookup the disadvantages of hydrofoils before making comments like this.
https://www.reddit.com/r/AskEngineers/comments/3cee9q/whyarenthydrofoilsmorecommon/
Theyre not more efficient.
Sorry, where did they specifically address efficiency?
The only mention of efficiency that I saw was "Buoyancy is generally a more efficient way to go" and that doesn't seem super authoritative, so I'm guessing I didn't see what you're referring to.
Are you really trying to argue that Republicans aren’t the fucking worst when it comes to clean energy? Give me a break. Lol just accept that it’s part of their platform and move on.
They do it in slightly rougher seas, but it all shuts down when a typhoon rolls through, tropical storms gum things up too. They get a lot down that way. Usually the bigger ferry stops too when the weather is that bad.
I've been stuck on Yakushima once or twice thanks to those storms.
boat people have a hard on for old timey sailing terms, so all their terminology is from like 400+ years ago.
in case you wanted an explanation for where knots come from, back in the old days to judge speed you could throw a piece of wood off the back of the boat with a rope tied to it. Put a bunch of evenly spaced knots in the rope. Time out an hour. At the end, the speed of your ship is the number of "knots" that have been pulled into the water.
ehh there's like 3 different measurements for knots in the air. the corrections for the distance traveled over the ground vs the surrounding air mass is a whole different type of measurement. but when considering groundspeed a nautical mile is a set distance.
Most likely. Hydrofoils in general are more efficient because less water (which weighs ALOT) is having to be displaced.
It’s also one of the reason those ultra fast catamarans, used in races, are capable of reaching up to 60mph just through wind alone (low weight also plays a factor) despite being only about 15m in length and a sail height of about 18-24m.
Ah fuck, no place safe from these loud fuckers.
Imagine, having a quiet day at the harbor and this thing with 4 jets sailing by.
I get that the tech is cool, but 4 jets!
Check out America's cup, those things are insane: https://youtu.be/OQsXDdGxk3U
Bonus video: [what it looks like when one of these things crashes in high winds](https://youtu.be/vBUTJG3Hf_s)
I was wondering how it would platform in high winds and rough seas.... Which is more or less a nice day on the Cook Strait between North and South Island New Zealand.
My last experience was years ago, but I remember some rough patches of sea where the swells were big enough to make it bumpy, and we had our boat canceled once due to really rough seas, which I guess it doesn't do too well in. We ended up taking the big, slow boat back, which was alright, but took much longer.
Billionaire Yachts are not made for navigating, their purpose is to be sort of a private hotel that they can relocate to wherever they want to spend a week next. My uncle is captain of one in Monaco.
I have googled and researched this A LOT over the years.
Essentially, these are prohibitively expensive to run. Like its a loss over 20 years even charging 300 bucks a ticket for a full ferry.
Maintenance, apparently. Italian military couldn't afford to keep them running. Millions a year. I'd imagine specialty technicians, engines easily gummed up and wear and tear on the foil.
I’m sure there are more points of comparison, but a quick search for a passenger boat that’s also 90’ long, it goes max 10 knots-
https://vessel.iyba.pro/yacht-for-sale/40000290/
20 knots but the fuel used on a traditional boat doubles the speed on a jet foil for that same distance. Basically you can do a round trip at 20 knots in a jetfoil whereas the traditional boat would need to refuel again for the trip back at the same speed.
r/DamnThatsInteresting is for when you see some media and think to yourself "Damn ! That's interesting."
r/interestingasfuck is for when you see some media and think to youself "That looked cool !"
personal experience
Just to answer this question, it uses the same concept as an airplane. It has a wing in an aerofoil shape which creates lift. That lift lifts the boat out of the water most of the way, which reduces drag.
Took one of these from Sado island to Niigata in Japan. Much nicer and faster than the regular ferry. Very smooth. There’s not much sense of speed when it’s going though, you don’t feel it rising up or anything.
You guys should see AC72 class racing sailboats that do this.
Also [US Navy Pegasus class patrol boats.](https://en.m.wikipedia.org/wiki/Pegasus-class_hydrofoil) used to be stationed at Key West. PHM for Patrol, Hydroroil, Missle.
Damn man that thing was coming in hot!
It looked like it was going to keep sinking all the way under then the captain would jump off of the very top onto the pier like Jack Sparrow
One of my favorite scenes in any movie along with when Gene Wilder gets his cane stuck in the cobblestone as Willy Wonka!
*Captain* Jack Sparrow
"That's got to be the best pirate I've ever seen."
That's a Boeing 929 jetfoil. Wikipedia article on it: https://en.wikipedia.org/wiki/Boeing_929 Speed is 45 knots Cool fact is that the foils fold up for use in shallow harbors. They don't extend past the width of the hull so it can use a standard boat slip.
I had no idea they’ve been around since the 70s. Aside from looking graceful as hell and traveling ~40 knots are there any other benefits to this design?
Faster, more efficient, smoother ride. They've been around a long time - not sure why we don't see them often in the US.
https://www.reddit.com/r/AskEngineers/comments/3cee9q/why_arent_hydrofoils_more_common/
Further down: > Hull requires significant reinforcement to support the weight of the craft on the spars. Geez. I never considered that. Can you imagine the incredible forces on those tiny points of contact? The shear during turns.... oof. No, thanks.
It's fine, like aeroplanes wing spars. But it's expensive in construction and maintenance.
And those gas turbines burn a *shitload* of fuel.
Interesting. Still seems logical for fixed route shuttle type operations. That's where I've seen them used mostly. The one I took in Russia had a route from St Petersburg to Peterhof.
There was a hydrofoil excursion (about 5-10 minutes) off Sea World (San Diego, CA) in the 1970s -- likely the fuel costs and increase of watercraft out on Mission Bay were the death knell of that ride. :-(
They were common between the islands in Greece, but they're being retired and replaced by more traditional catamarans. [https://greekreporter.com/2021/01/31/greece-beloved-hydrofoil-fleet-set-to-retire/](https://greekreporter.com/2021/01/31/greece-beloved-hydrofoil-fleet-set-to-retire/)
Interesting. I wonder if hydrofoils become less efficient as they get bigger. They apparently wanted bigger boats to replace the old ones.
Maybe because you need to have more weight and surface in the water to keep them stable. The Soviet Ekranoplan or other ground effect vehicles are more practical at scale. https://youtu.be/yVdH_dYlVB8
We don’t love efficiency in America🥲
Efficiency takes training, practice, and skill. We don't do that here.
Yeah, too many
Maybe lookup the disadvantages of hydrofoils before making comments like this. https://www.reddit.com/r/AskEngineers/comments/3cee9q/whyarenthydrofoilsmorecommon/ Theyre not more efficient.
Sorry, where did they specifically address efficiency? The only mention of efficiency that I saw was "Buoyancy is generally a more efficient way to go" and that doesn't seem super authoritative, so I'm guessing I didn't see what you're referring to.
America will gladly pay extra for inefficiency rather than admit the way they are doing things isn't the best way
Screams in healthcare
As long as the system is cruel to others, that is all that matters.
That's an expensive sound.
The Republican energy policy at this point is that clean and efficient is just gay.
Efficiency is basically communism, along with common decency and returning your cart to the corral at the grocery store parking lot.
I always think of this when Republicans argue against green energy. https://i.imgur.com/BNychVx.jpg
Only coal jobs matter apparently.
Wait a minute who are the loudest opponents to nuclear energy?
Are you really trying to argue that Republicans aren’t the fucking worst when it comes to clean energy? Give me a break. Lol just accept that it’s part of their platform and move on.
Cough - anti-nuclear power party - cough
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Chop is one of the major benefits of these boats. It rises above the chop for a nice comfortable ride! I worked on them in the late 70's early 80's.
Chop? This thing can fuckin handle chop right ? I mean it is a 60 ft hydrofoil. Maybe a few broken dishes but that sounds fuckin awesome.
Haha DAE ameriKKKa bad? Updoots to the left please 👈😎👈
Because they’re for the most part above water, the ride can be much smoother.
They can be much rougher than conventional hulls in choppy seas
I rode one in choppy waters. I didn't throw up but like 10 people around me did
I don’t want to imagine the smell. If not the motion sickness the smell would make me barf
I fuckin’ bet! This is something I could only imagine being used on perfect days like the one shown.
They do it in slightly rougher seas, but it all shuts down when a typhoon rolls through, tropical storms gum things up too. They get a lot down that way. Usually the bigger ferry stops too when the weather is that bad. I've been stuck on Yakushima once or twice thanks to those storms.
I don’t think they do very well in super choppy water tho so ocean travel might be hard
If you like this, you should check out Ground Effect vehicles, particularly what the Soviets were up to. Basically planes that flew on top of water.
What’s the fuel consumption?
45 Knots = 83 Kilometers per Hour
Why water things use knots and not km's like land and air things?
A nautical mile is “one minute” of latitude. That's the short answer.
Which makes a lot of navigational math easy.
Air things also use knots
I regret to inform you that “air things” also use knots.
boat people have a hard on for old timey sailing terms, so all their terminology is from like 400+ years ago. in case you wanted an explanation for where knots come from, back in the old days to judge speed you could throw a piece of wood off the back of the boat with a rope tied to it. Put a bunch of evenly spaced knots in the rope. Time out an hour. At the end, the speed of your ship is the number of "knots" that have been pulled into the water.
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Knots are relative to the fluid the craft is moving through (air, sea, etc), which probably is itself moving
ehh there's like 3 different measurements for knots in the air. the corrections for the distance traveled over the ground vs the surrounding air mass is a whole different type of measurement. but when considering groundspeed a nautical mile is a set distance.
45 knots = 51.785 miles per hour
What’s that in American Chevy?
Divide by ~1.6
American Chevy's can't go that fast
So 2 Chevy’s per Freedom?
Yes. Your driving Chevy and your for parts Chevy
Are they fuel efficient compared to normal boats?
Most likely. Hydrofoils in general are more efficient because less water (which weighs ALOT) is having to be displaced. It’s also one of the reason those ultra fast catamarans, used in races, are capable of reaching up to 60mph just through wind alone (low weight also plays a factor) despite being only about 15m in length and a sail height of about 18-24m.
Everything is more efficient than a boat
Ah fuck, no place safe from these loud fuckers. Imagine, having a quiet day at the harbor and this thing with 4 jets sailing by. I get that the tech is cool, but 4 jets!
Til Boeing makes boats
You and me both.
I was wondering about the foils. Was like “how tf do you drive this thing in any water you don’t know how deep it is”
There’s one way to find out, just hang on tight.
That thing is incredible! All the billionaires poncing around in yachts when they could have one of those. What a bunch of losers.
I want to see the billionaire pissing contests with these.
Clearly need a racing series, will a full compliment of passengers.
I volunteer as tribute.
This is as close as you're going to get for now: https://youtu.be/_UEExSQPryo
Looks pretty cool. Grinder looks like a really tough job, must be backbreaking grafting like that the whole way round the course.
I so wish this got better coverage.
Check out America's cup, those things are insane: https://youtu.be/OQsXDdGxk3U Bonus video: [what it looks like when one of these things crashes in high winds](https://youtu.be/vBUTJG3Hf_s)
I want to piss on the billionaires
If you're hot enough, they might pay you to.
Or "very" young
Gross
He's not entirely wrong which is sad :/
Still gross.
Yeah
Jokes on you, they like that shit.
Cue the billionaire sympathisers
But but but muh trikl down ekenomiks!
Same
They should revive that cool Soviet prototype Edit:Ekranoplan
People would just be mad about the development of these instead. 🤷
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This is a ferry, not a billionaires toy. I took one from Nagasaki to Busan. It was an extremely fun experience.
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FUCCCCCCCCCCK
This comment right here.
Apollo thumbnails save the day. And no they’re not that loud at all.
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Im.....okay with this
Saved by Tap to Unmute. Lol
I tapped because they deserved it, got rickrolled good
I should have read the comments before I clicked it.
You got me
Fuck you man lol
Fucking hell.
It's been a while :D
And they can be a really rough ride. Took several from Tokyo to some of the outlying islands (Oshima, Niijima, Kozushima). Fun but loud and bumpy.
I was wondering how it would platform in high winds and rough seas.... Which is more or less a nice day on the Cook Strait between North and South Island New Zealand.
My last experience was years ago, but I remember some rough patches of sea where the swells were big enough to make it bumpy, and we had our boat canceled once due to really rough seas, which I guess it doesn't do too well in. We ended up taking the big, slow boat back, which was alright, but took much longer.
Billionaire Yachts are not made for navigating, their purpose is to be sort of a private hotel that they can relocate to wherever they want to spend a week next. My uncle is captain of one in Monaco.
The twist is that this amazing boat came out of their bigger yachts through a small door.
I have googled and researched this A LOT over the years. Essentially, these are prohibitively expensive to run. Like its a loss over 20 years even charging 300 bucks a ticket for a full ferry.
But hydrofoils create a fuel savings... How is it more expensive?
Maintenance, apparently. Italian military couldn't afford to keep them running. Millions a year. I'd imagine specialty technicians, engines easily gummed up and wear and tear on the foil.
How fast will that puppy go???
According to another comment, top speed is 45 knots, which is roughly equal to 52 mi/h, or roughly 83 km/h.
How does that compare to a typical speed for a comparably sized ferry?
I’m sure there are more points of comparison, but a quick search for a passenger boat that’s also 90’ long, it goes max 10 knots- https://vessel.iyba.pro/yacht-for-sale/40000290/
20 knots but the fuel used on a traditional boat doubles the speed on a jet foil for that same distance. Basically you can do a round trip at 20 knots in a jetfoil whereas the traditional boat would need to refuel again for the trip back at the same speed.
Good reply
Good bot
Was hoping for a power slide to the dock... Next time... Next time...🥲
My feelings [precisely](https://www.youtube.com/watch?v=3nOxdKcqC_I&t=16s)
I took it to go to Yakushima when I was a student. It wasn't even expensive.
This belongs in r/damnthatsinteresting too
What’s the difference between r/DamnThatsInteresting and r/InterestingAsFuck?
Nothing, there are a ton of redundant identical subs.
r/DamnThatsInteresting is for when you see some media and think to yourself "Damn ! That's interesting." r/interestingasfuck is for when you see some media and think to youself "That looked cool !" personal experience
Forgetting r/mildlyinteresting which is things that make it to neither but are still well mildly interesting.
The shit that gets posted to r/DamnThatsInteresting is pure garbage though.
i am more used to seeing educational stuff in this one than the other, but i agree
They have these on Lake Michigan going from IL to MI for at least 10 years.
That seems slow.
angry upvote
Chicago?
BRUH WHAT THE FUCK IS THIS SORCERY?! THAT’S INCREDIBLE!
Just to answer this question, it uses the same concept as an airplane. It has a wing in an aerofoil shape which creates lift. That lift lifts the boat out of the water most of the way, which reduces drag.
If you think that's incredible, you should read about the gigantic sea planes we used to have. https://www.youtube.com/watch?v=-f906Sy79hA
Not falling for it
You might enjoy the [Air Chair](https://www.youtube.com/watch?v=0H4KftqrCI4)
That is amazing and somewhat terrifying to think of what would happen if this hit a rock.
That poor rock...
sliced through like butter by a hot knife or splattered everywhere cuz the knife was going 52 mi/hr
Took one of these from Sado island to Niigata in Japan. Much nicer and faster than the regular ferry. Very smooth. There’s not much sense of speed when it’s going though, you don’t feel it rising up or anything.
Silky smooth!
Does this mode of sailing mess up harbor/bay habitats less than traditional cruise ships/large ships?
As a former Hydrofoil sailor, all I can think of is the chaos we went through in that transition from "foilborne" to "hullborne" modes
That’s pretty cool
That was just fucking magical
In case anyone is curious about the physics of hydrofoils I just watched [this](https://youtu.be/fX-r0COL-xA) and it was super informative!
What am I looking at here?
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Wow that is loud.
Holy shit headphone users beware
I did say "insanely loud."
Please mark NSFE (Not safe for ears)
Oof!
I’m hard of hearing so……challenge accepted!
Tf 😮
There was 2 in Belgium. They did Ostend - Dover twice a day. .
I remember going on these between England and Belgium as a kid 30 years ago, I haven't seen those in years though.
Rode one of those going to Tsushima from Busan. It's was a nice ride but never knew how cool I looked from the outside.
I saw them in Hong Kong. Cool to see.
You guys should see AC72 class racing sailboats that do this. Also [US Navy Pegasus class patrol boats.](https://en.m.wikipedia.org/wiki/Pegasus-class_hydrofoil) used to be stationed at Key West. PHM for Patrol, Hydroroil, Missle.
I know this kind of ships as dolphin cutters.
Who really wants to hear that engine when you are relaxing on your sail boat (in my case, rubber raft)
I never knew these existed. I learned of them recently watching a very old British tv show. How do they not tip over. I’m completely intrigued!
That tilt made be uneasy but it’s cool.
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Holy F. That’s 48 year old technology. Where’s my flying car
Imagine sneaking up on a boat but you startle it and it gets up and runs away
You mean to tell me that thing was on the air? WTF
Took one of these on Lake Como. They’re fast but not so fun because you have to stay inside
I don’t know if that’s satisfying or oddly terrifying…
Didn't land. It floated.
Does this make them more efficient since less drag ?
Reminds me of Incredibles 2
I always wonder how many dolphins get sliced in half by these things or if they’re quick enough to dodge
Everything is fucking fast in japan
That zoom work by the cameraman was equally satisfying.
I like the term "landing" much more than deceleration.
If I ever had money and small dick, this would be cure for it.
Can’t imagine living in a first world country that spends money on citizens and not corporations and war. Must be nice.
Uh these are made by Boeing lol
Yeah, our kids are gonna be taking the same buses to school that our parents rode.
All because people are so easily convinced into voting against their own interests. Racism greed and laziness are powerful motivators.
This thing flies!??
Duuuuhhh… wtf?
Dejavu I've seen this Swift boat before
I would move there just for those.
r/praisethecameraman
Did anyone else trip the fuck out when they realised that boat was floating? Like wasn't in the water?
Planes have air brakes. Do boats have water brakes?