Speed Boat on skis

I have joined this conversation very late in the piece, but for others who might follow, I have the following to offer as the originator and builder of the Sea Ski prototype in question.

Firstly, may I dispel a few doubts. The little prototype (6.4m, 1.5t & 225hp) handles seas and chops very well indeed, in fact much better than its long established peers (on a size for size basis). Anybody who wants to go out in 25 knot winds in small craft doesn't deserve to return home, but built in flotation can save the day.

In company, I did a trip on Tuesday (24.5.11) from Pt Danger to Brisbane (Australian east coast) being a distance one-way of 140 km of sea, bay and river in 2 hours 20 min. The seas off the Gold Coast on the way up were 1.02m average with 1.7m significant waves and with some pretty kicky water between the swells. The speed was constant throughout the journey. The return across Morten Bay (a big shallow expanse) had 12 knot astern winds raising a 2.5ft chop - no problem at all.

Regarding the aesthetics or design. I am a retiree on a shoestring budget. It took years to scrimp together the money and build this vessel as economically as possible. I had one objective only; to find out whether my ideas were sane! If we raise the capital from investors, the production model of 9m (30ft) will be properly designed by a naval architect. Beauty is very easily applied, even I could do it, and I am a boy from the bush of Africa whose dress sense was always khaki, khaki and khaki.

For the designers that are interested in the workings of the vessel and its scale up, I would suggest you think of aircraft, their weights and stall speeds and then take into account a phenomena known as the wing-in-ground effect, or WIG, which is experienced by landing aircraft.

The vessel is intentionally flat bottomed with sides extending below the hull to connect with the skis and use the forward propulsion to drive the skis up onto the surface and thus compress air under the flat bottom. So the faster one travels the more air compressed, the lighter the weight on the skis and the lighter the load on the motor. No rocket science, Scotty!

To Tom Kane, thank you for the info on the New Zealander who did something of the kind in 1915! He was one intrepid designer for his time, given he didn't have powerful and fast outboards to work with, or light and strong aluminium and probably knew nothing about aero dynamics; the Wright brothers only having taken to the air 13 years before!

Beam me back down, Scotty! There's something I need to look at again.

 

Here is a video of someone taking the idea of lifting the hull above water a little further:

http://www.youtube.com/watch?v=w54-OEWulDE&feature=related

My son sent me the link and suggested I do something similar with my boat, but I don't like the idea of a laptop controlling the hull position.

 

Watch the video posted, they show and tell all. Low wake, higher speed per given fuel consumption and HP used, roll stability.

I'm shocked that the ski's don't curl up more like Santa's sled at the bow. Looks like the ski's cut through the water at lower non-plane speeds and through waves.

This design is a twist or cross between the skirtless SES using catamaran like but thinned side walls and a true ski machine like the Sea Phantom.

http://www.globalsecurity.org/military/systems/ship/hsv-gallery.htm


http://www.wired.com/gadgetlab/2007/06/sea-phantom-7-1/


Regarding the high costs of this craft, somebody has to pay for the 10 years of development and the prototype. Still it will take a while to recover the cost in fuel savings.

 

From what I understand Naval Architects are more like engineers than Industrial Designers. Not that it's a bad thing, but you might want to consider using both. One who can incorporate the "pretty" of a visionary Industrial Designer with the engineering and construction considerations.

Think of it as building your dream house. Sure, you could design it yourself, but to express your ideas even better hire an Architect. He in turn may hire a structural engineer, civil engineer, Mechanical, Electrical, Plumbing Engineer, and Landscape Architect to make it all come together. Of course it's all worthless unless you have good contractors too.

I'm an architect (not naval) who does some Industrial Design and would love to help you. It might be even more wise to look at David's (Rambat's) portfolio/credentials at Industrial Object.

 

Captain Kirk was a boater?

 

If there were excited green women to be found on boats, he would be a boater!

--
CutOnce

 

A reply to Sea Ski designer.But a Kiwi did fly before the Wright Bos. Richard Pearce.

 

glad you mentioned that tom. i never hear much about that flight. every time i see programs about the wright brothers it reminds me of it. it shows how we are conditioned to believe what big brother tells us. i for one would love to see your kiwi pilot get the recognition he deserves.

 

I did not know this name before, thanks for posting it.

Link:
http://www.ctie.monash.edu.au/hargrave/pearse1.html

A year before him there was taking to the skys Gustave Whitehead.

Gustave Whitehead
http://gustavewhitehead.org/

SeaSki Designer; what is the main body material; plywood, Coosa, other foam, honeycomb?

The Galileo space shuttle looks don't bother me at all, it makes a lot of sense to get started that way so that the important things below it can get sorted out first.

http://www.engsoc.org/~pat/log/index.cgi/2005/05/index.html


I like this later version too. Maybe keep the theme going in the Next Generation?

http://en.wikipedia.org/wiki/Shuttlecraft_(Star_Trek)
http://en.wikipedia.org/wiki/Shuttlecraft_(Star_Trek)

 

If our Richard pearce did not receive recognition our latest inventor certainly will.Just imagine flying in a jet pack at 5.000 feet.Google flying kiwi jet pack

 

Reply to Kach22i. The prototype vessel is all aluminium, being off-the-shelf extrusion and sheet. The skis are made from 4mm (0.16in) sheet with internal reinforcing (x-section, front on, looks like a D rotated 90deg counterclock), flat hull bottom is 3mm, sides 2.5mm and topsides 2mm.

 

Many pioneers of aviation flew before the Wright brothers. What makes the Wrights notable is that they did real research into the dynamics of propulsion, lift and control of aircraft before attempting powered flight. All their flights were also well documented and they flew in competitions against other pioneers to establish the value of their developments. None of this denigrates the work of others like Pearse, Clément Adler (1890), Alexander Mozhaysky (1894), Hiram Maxim (1894), Santos Dumont, Langley, Chanute, etc, etc.

No one in that era matched the body of scientific investigation and engineering of the Wright brothers. The evidence is available in any public library or web terminal for those who are willing to study it. The main fault of the Wrights was their almost paranoid fear of others taking undue advantage of their work and so they were too secretive for their own good.

What the Wright brothers demonstrated, that none of the others did, was to take off under power, control the aircraft, fly a predetermined path and land, still under control. Not all of that took place on the first flight but they did so before anyone else accomplished it. Anyone objectively looking at the evidence would conclude that the Wrights deserve their recognition as the first in flight.

 

Congratulations on your design. I thought the video on your website was quite impressive. That prototype really gets up and moves, even in the open water. I would like to see what it does with some steep chop. I am guessing the skis will slice through small steep waves, so as long as the tunnel doesn't get slapped you should get a smooth ride. Unlike many "innovations" with small power boat design, you seem to have come up with something that actually does work. The difficulty I see will be overcoming the inherently boxy lines that come with the straight skis and large flat bottom, to turn it into an attractive recreational boat. For commercial applications like water taxis, small patrol boats, etc, the boxy lines might not be a problem.

The skis also draw a bit more water than a conventional hull when you are at rest, but that is probably not a huge problem. I also wonder about maneuverability. I suppose it would act much like any power catamaran. Good luck with it!

 

Thanks for your encouragement, Intrepid 71.

Regarding your concerns about handling a chop, the design does it very well without "slap" in the tunnel. I am not sure whether you have driven cars on badly corrugated dirt roads, but if you have, you will know that at slower speeds you experience a lot of discomfit, whereas at high speeds, the corrugations are considerably more bearable. Not a good idea for novice bush road drivers, though, but the Sea Ski is very safe and holds a straight line.

Maneuverability in open waters is quite acceptable, but at 50mph + it is not the sort of vessel you would want to be throwing through a tight and winding water course.

The boxy lines can be rounded out somewhat, but at extra expense!

 

Visitors to this thread may like to read this review done by the editor of Powerboat-World.com (http://www.powerboat-world.com/Is-this-a-'new-era-of-hull-design?/83665), who was a former champion Australian offshore twin-hull racer. It is, todate, the only independent review done by somebody who has driven the boat other than the designer. There was an unintentional inaccuracy in the story describing the prototype's "cruising" speed as 90 km/h (49 knots) whereas that is the fastest speeds I have been prepared to travel at.