Please knock down stupid idea

You are correct about the dollars. It really is a key reason I am beginning to explore the concepts. 500k doesn't buy much on the "NEW" sport fisherman market. I'm with your brother in law. If that things does cool stuff, I'd fish it in a new york second.

Oh, don't forget the blender and plasma. I like to watch the college football games when the fishing is slow. Go hokies.

 

If I remember right, a big problem with hydrofoils is dynamic stability and control. For example zipping out to the gulf stream takes you through choppy conditions, fluctuating angle of attack on foils, variable lift, oops, bow dips.....
ahhhhhh pitchpole at 70 knots!

 

You needed investors just to pay the patent lawyer fees I assume. Under six figures? Under seven?

I'm looking at all the spray being kicked up in those photos, from what I've been told not a good idea for Special Operations team delivery.

The guy I talked to about my own preliminary military hovercraft design four years ago said the RIB/outboard roostertails show up on radar letting everyone know you are coming - very bad.

They also like to use foul weather as cover, so a taste for heavy sea states (4?) are a must.

The part on the SeaPhantom website about injured/crushed spines and forced early retirement for Special Opps is a real concern, heard that first hand too.

Pitching and heaving is okay, shock and impact not so good, the SeaPhantom is very interesting in this regard - at least for me.

 

I love these boiled down rules of thumb.........keep them coming please.

 

............and they would be?

 

A second brother-in-law was a SEAL. Used to hang out on the Base @ Little Creek when I was in Boy Scouts. Saw body damage first hand. Most of the big spray in photos is from shots of high-speed bank turns (inboard foil dipped), or, just comming up on foils. Lots of spray then, but looks cool in photos. Once fully airborne, less than 16 square inches total in contact w/water. Not much there to make spray with (except prop). We'll be working with a military suspension contractor, whose background was Baja cars, to fit active suspension to maintain stability in nastier seas. The goal is 85knots over tops of six footers. (obviously outboard no longer adequite- going w surface drives and diesel turbine- no need for colling water pick-up))

Averaged six-to-nine hours working for someone else to buy each and every one of the more than 3000 hours it took to build. Plus several hundred$k cash. A Fortune500 analyst that came by my shop estimated the value spent was between $1.3 and $1.5 mil. But it was really just ten years of hundred hour work weeks.

 

Originally Posted by FAST FRED
Surface drives have their own numbers.

............and they would be?

Sorry , I seldom remember stuff for boats I cant afford,

But another good rule of thumb is a gas engine will give 10 to 12 hp for every GPH

The old diesels (detroit 2 stroke or Ford Leman) will give 16 hp the 90's designs about 18 ,with turbos can get to 20 hp ,
and the electronic controlled ,dual wastegate turboed and INTERCOOLED diesels can get to 22 or so.

Untill the fuse blows, or the lightning strike.

Pick a diesel size that should run at 75% power 75% of the time, try for 90% power at 100% rpm, not "rated power".

If you frequently operate for long periods of time under 20% - 25% Rated hp you may have big troubble from underloading , wet stacking and excessive blowby from burnished cylinder bores.





FAST FRED

 

I don't remember this important fact being covered in the diesel/elec hybrid drive system thread a couple of months ago.

How diesel-electric propulsion saves fuel
http://ossapowerlite.com/tech_library/fuel_efficiency/fuel_efficiency.htm

 

That is understandable, watching most hovercraft shows similar conditions and spary results although for different reasons.

The RIB's used in special opps can kick up spray because the craft may become airborn in tall waves causing the propeller to go in and out of the water at various angles of attack. Quite the show from what I've read, but I have no first hand experience on this I must admit.

100 hour weeks for ten years?

You need a vacation.

 

Air Screws

The best real world results for airboat props is about 4 lbs per horsepower.

Casey Baldwin, with support and financing from Alexander Graham Bell, set a water speed record of 70 mph with a hydrofoil boat driven through air screws.

 

Pretty tired now

100 hour weeks for ten years?

You need a vacation.[/QUOTE]

Thanks, really really tired now. Just launched five weekls ago, only need to sell one now. Have molds to reproduce. Did just get back from Bamahas - thanks to my amazing wife! Ended up scouting out potential operating sites. Lots of islands need fast transport. Sure hope.

 

Just put the old skull and crossbones on the vertical fin and you have the perfect pirate ship........................and of course the idea location will be close to your clients - the Bamahas or off the Ivory Coast.



related thread:
http://boatdesign.net/forums/showthread.php?t=4049

 

you know, I built a lot of alloy sportfishers
I started with wide chines, fairly shallow deadrise forward, in other words spoonish shaped entry, 17 degree deadrise aft and monohydran
After having the hell smacked out of me and the boat,(they were great downwind) I changed to very very steep deadrise forwards, sharp entry, I use one short strake forwards and the wide inbuilt chine
look at the desIgner DON SHEAD UK his very large motor yachts are like this
I found that I could power on over the roughest sea, landing was soft, stabilty downweather good I found that I could leave everything behind, the former config being down to disp. speed in the rough
Adding strakes just added to the hard ride, and gave nothing in return there is nothing to be gained in big vee aft, just makes the boat roll.
I would stick with this type of hull, odd things scare the hell outta of buyers when sale time comes around

 

100% true, no argument from me.

However.........................as with the Sea Dart, some things keep coming around and around until the technology comes around and finally sticks.

Newer stuff:
http://www.vtplc.com/halmatic/product.asp?itemID=414&catid=92



And from the Anicient Greeks.............................






............and as for ski's there is nature's models.

 

Although ducks when landing on ice can get hurt (no control), water landings are natural for them, something of a show though.