RichR
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Registered: 17th Oct 01
Location: Waterhouses, Staffordshire
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Wave Piercing Hull Design
Wave piercing technology was originally formulated for passenger ferry applications, and more recently it has been applied to military craft.
Wave-piercers have a very fine bow with minimal reserve buoyancy in the forward portions of the hull to minimize vertical motions. When a wave is encountered, the hull pierces through the water rather than riding over the top. The result is a dramatically smoother ride than traditional deep-V designs, minimizing stress on the vessel as well as the crew.
Wave piercing is a key element in getting the record for circumnavigating the globe. It allows the boat to run continuously at high speed in both flat and rough sea conditions.
Following is a simulation of how Earthrace pierces a series of waves. This mathematical model was developed by Germanische Lloyd using Star CD software from CD-Adapco, and the results have been crucial in ensuring Earthrace can withstand the enormous forces involved in passing right through big waves
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Daimo B
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Thats a 15m wave. But the difference with those kind of waves is that its one peak forced upwards as it gets closer to land and all water mass is forced up and forwards.
Where we ski'd had a large flat sand plane, so there the waves were higher and shorter at sea, as they'd get closer to land, they would reduce in height and get much longer.
Steve, no I haven't, not so clever if you can't read....
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Daimo B
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quote:
Originally posted by LiVe LeE
Errr thats probably £500,000 worth of boat. Thats also a triple hull, not a singular v hull as on 95% of speedboats.
Not a 19ft Fletcher with outboard thats moored up to close to the shore.
yes boats are shite compare to a jetski IMO... Can do far more tricks on a ski and have a lot more fun, we've had both.
Comparing a jetski to an offshoare power boat is like comparing a scooter Vs a Supercar..........
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AK
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and thats not really rough sea either 
1.5m swell or something
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AK
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this is better
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AK
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Location: Aberdeen City
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this is actually quite a good pic... its really liek that coming towards yuo... big rolling swells
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AK
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Daimo - sorry... I just cant get my head round anyone in their right state of mind jetsking in 20m swells.
I've been on boats 100+m long 30m wide in those sort of seas and there is no way a guy on a jetski will last long in the north sea (dry suit or not) in those conditions.
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AK
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this is maybe 8m seas -
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Daimo B
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Dude, i've not said i do 20m waves? Steves saying that.
I said about going over 8-10m waves and seeming like 20m waves over the other side with the void that the previous wave has created......
That lat pic, ski'd in much worse than that, but not quite the double barralled wave you've posted previous. That (form picture angle) is a big ass set of waves.
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Daimo B
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quote:
Originally posted by AK
and thats not really rough sea either
1.5m swell or something
If that i'd say...
That last pic has quite high winds too, you can see the way the water is pushed off the top of the wave to create the white tips. They are long roller type waves.
[Edited on 09-11-2007 by VXR]
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Jay
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quote:
Originally posted by Matt H
So who's got their feet wet then?
Anyone whos not on, theyve lost power
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AK
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Registered: 5th Jul 00
Location: Aberdeen City
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a 10m wave (wave height) is 10m from top to bottom
are really trying to say a 5m amplitude, giving 10m height?
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Daimo B
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Yeah getting wires crossed here.
Im meaning a 10m wave, is 5m viewable from the front, but as you go over is, you have the 5m wave, plus the 5m void gap of water that the wave has just sucked up.
So if for example, the water is dead calm, then 2 random 10m waves approach, you would only see 5m of height on the first one, then a 10m drop behined it, followed by a 10m wave, then as you dropped down the 2nd wave, it would be another 10m drop, then only raise again 5m back to sea level (2 random wave, jsut an example).
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RichR
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Registered: 17th Oct 01
Location: Waterhouses, Staffordshire
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quote:
Originally posted by AK
and thats not really rough sea either
1.5m swell or something
I couldn't find the wave piercing footage otherwise I would have posted it; the Earthrace has been down through the southern oceans; the footage of it literally completely submerged is stunning! 
[Edited on 09-11-2007 by LiVe LeE]
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RichR
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Registered: 17th Oct 01
Location: Waterhouses, Staffordshire
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quote:
Originally posted by VXR
quote:
Originally posted by LiVe LeE
Errr thats probably £500,000 worth of boat. Thats also a triple hull, not a singular v hull as on 95% of speedboats.
Not a 19ft Fletcher with outboard thats moored up to close to the shore.
yes boats are shite compare to a jetski IMO... Can do far more tricks on a ski and have a lot more fun, we've had both.
Comparing a jetski to an offshoare power boat is like comparing a scooter Vs a Supercar..........
Its not a Trimaran, its a mono hull with outriggers actually 
Plus you said "Boats" not speedboats, yachts, powerboats, fletchers, RIBS - but Boats - that is a boat!
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AK
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ok... makes more sense... i thought for a minute there you were going to say 'Seem that wave in Perfect Storm' I was there
I'm taking 16m+ constant rolling waves.... with 90+mph winds.
I headbutted a wall on a boat once it was listing so bad just couldnt stay on my feet and flew across the room head first into a wall, then a sofa landed on me
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Daimo B
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quote:
Originally posted by LiVe LeE
Its not a Trimaran, its a mono hull with outriggers actually
Plus you said "Boats" not speedboats, yachts, powerboats, fletchers, RIBS - but Boats - that is a boat!
Picky git But your right  Its a big SeaCat to me That one of those serious Atlantic type race boats? Don't really get much in the form of boat racing in the UK, always loved the offshoare power boats. 160+mph on water, feck that....
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RichR
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Registered: 17th Oct 01
Location: Waterhouses, Staffordshire
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Seacat - catamaran - in no way a trimaran
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RichR
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Location: Waterhouses, Staffordshire
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VXR/AK
Can't find the live footage, but this was pre-build trials concepts
http://assets.earthrace.net/vid/waves%20web%20H.wmv
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Daimo B
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quote:
Originally posted by AK
ok... makes more sense... i thought for a minute there you were going to say 'Seem that wave in Perfect Storm' I was there
I'm taking 16m+ constant rolling waves.... with 90+mph winds.
I headbutted a wall on a boat once it was listing so bad just couldnt stay on my feet and flew across the room head first into a wall, then a sofa landed on me
Water is not to be messed with We will loose
Thats also what you don't need to worry about on a ski as its only 2m long But being so short means if the nose does hit the front of a wave (we call it Submarining) and goes straight under. It hurts, quite a lot usually though you can just ride them out and go up and over the waves, where as in a boat it'll cover more that one wave usually hence all the tipping and swaying.
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Daimo B
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quote:
Originally posted by LiVe LeE
Seacat - catamaran - in no way a trimaran
They classed at catamarans with the central hull? Always considered them to be tri hulls.
LEarn summit new every day.
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RichR
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Location: Waterhouses, Staffordshire
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not the seaCAT
Central 'hull' does not come into contact with the surface water; it actually allows greater stability and spray diversion - as opposed to being a 'hull'
[Edited on 09-11-2007 by LiVe LeE]
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Daimo B
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quote:
Originally posted by LiVe LeE
VXR/AK
Can't find the live footage, but this was pre-build trials concepts
http://assets.earthrace.net/vid/waves%20web%20H.wmv
Wicked, if it "submarines" it cuts through the water smoothly, probably maintaining speed too. Skis will hit the water, and stop, unless your on the throttle. Although you can do tricks to force them under the water as part of "freestyle" tricks.
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Daimo B
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quote:
Originally posted by LiVe LeE
not the seaCAT
You can see why i'd think it was a triple...
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Steve
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Registered: 30th Mar 02
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daimo gets pwned again
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