Alternative Propulsion And Hulls

[spiel_mit_feuer]

i am interested in alternative propulsion, engines, for smaller yachts, between 30-40 feet.. im interested in alternative technologies, electric motor diesel hybrids, hydrogen, biodiesel.. i have plans to build a boat soon, though im not sure whether im going 30 or 40 foot.. but id like to be able to take it across the oceans.. does anyone have any ideas or solutions? im also interested in higher tech style boat hulls such as hydrofoils, hover (im not sure that would be reliable enough though) and perhaps some ideas people may have that havent been built yet?.

[FAST FRED]

To cross even the smallest ocean SAIL is the simplest and least expensive way.

5000 years of experience preclude much Alternative.

Diesel is still the only way to motor any distance at a modest (or better ) speed.

High tech and alternate ideas are fine for mental masterbation , but for folks that want a boat in the next few decades , the tried and true marine solutions are all there is.

Big bucks can get a lighter construction , and if you have loads of cash a long long skinney boat will be easier and faster to push thru the wayer than a heavy roomaran box of a boat.

Select the "best" design for your Desirements , and find a boat builder.

FF

[spiel_mit_feuer]

i was considering going with either a cat, or planing monohull and try out a biodiesel/electric hybrid propulsion to see what sort of efficiency id achieve with the fuel, the cat could be both sail and power though, with more interior room which does lead me moreso into that direction.. anyone know about custom building a hydrofoil of 30-40 feet?

[FAST FRED]

but id like to be able to take it across the oceans..

Hydrofoil takes far more speed , to stay up , than most ocean cruisers can see on the best sailing day in a century.

I guess you have many many hundreds of thousands of Euros to experiment with , access to test tanks and research facilities , and enough guts that a few decades of no results will be part of the dream.

There are loads of non naval arch that will feed this dream for a good price.

Check out the Galcier Bay site for some ideas on very inefficient , but electric , propulsion.

For reality go to the Professional Boat Builder site and READ the articles by Nigel Calder concerning electric use for propulsion.

FF

[spiel_mit_feuer]

i wasnt planning to use sails on a hydrofoil (idiot)

[Kay9]

Ya know Feuer, Fred here is one of the better contributors on this forum and someone in which you should LISTEN too. Calling people an "idiot" that are trying to help someone that has NO IDEA what they are talking about or doing, is a sure way to end up talking to yourself and recieving NO HELP at all.

K9

[spiel_mit_feuer]

thats exactly my point.. you assume i dont know what im doing, such as he assumed i was actually talking about sailing a hydrofoil, i came into this forum to find people who would actually contribute to a discussion about alternative propulsion and hull designs rather than bombard me with their arrogance, and ignorance in assuming i have no idea what im talking about, and beginning their conversation with me in a condescending nature... so if anyone has anything positive to contribute to my post, then post if, if not, keep your mouth shut because i dont care to hear people who assume they know more than me, its not what i went to college for physics and engineering for

[FAST FRED]

" he assumed i was actually talking about sailing a hydrofoil,"

A sailing hydrofoil has crossed from SF to Hawaii about 30 years ago.

Guess you missed it,

FF

[spiel_mit_feuer]

i dont care what someone else has done, all i care about is what im going to do, so if youre not going to actually contribute something positive to my post.. why do you even both posting? or do you just enjoy coming into peoples posts to shit on their ideas or topics?

[Kay9]

Option "B" in your case.

[marshmat]

Must we go on like this?

SMF, you did ask in post #3 about custom building a 30-40' hydrofoil in the same line as you asked about a motorsailing cat. Fred shot the hydrofoil down. He may be a bit short on grammar skills (no offence, Fred), but the guy tends to be right an awful lot.

Now that it's clear that you're thinking cat (I think):

If you're after efficient powering and good sail performance in the same boat, I do agree that multihulls are the way of the future.

What I don't see happening anytime soon (unfortunately) is a shift away from diesel in favour of something cleaner and cheaper. There are some applications where diesel/electric is promising, but it is not a universal solution and the technology needs to come down in price a fair bit more. Fuel cells for yachts may be technologically feasible in a decade or so, but what fuel will they run on and will you be able to buy it in Vanuatu, Samoa, etc? Diesel will be with us for a while, although the source may shift from oil to biomass as the former gets more expensive and the latter more efficient. But the infrastructure and technology are there, so that's what we're stuck with for now.

[spiel_mit_feuer]

yeah, multihulls are a lot faster, efficient, etc.. but i could be doing a lot of sailing in the north sea, and sometimes north of the arctic circle, if a mutli-hull rolls, youre screwed, but a monohull will be able to take rough weather a lot better which is why im leaning towards a monohull design now, and since i do want to do a lot of traveling i think sails are the best way to go.. i thought about a hydrofoil power boat before but it just wouldnt be right for what i need, id love a hydrofoil, planing hull, or multihull if it fit into what i need in a boat, which it doesnt seem to right now

[kengrome]

i dont care what someone else has done, all i care about is what im going to do.This seems like a rather short-sighted argument since most people are anxious to learn from the things other people have done. Be that as it may, what are you going to do anyways? All you've done so far is mentioned a dozen different things. Can you possibly be a little bit more focused so we know what you actually intend to do?

i could be doing a lot of sailing in the north sea, and sometimes north of the arctic circle, if a mutli-hull rolls, youre screwed, but a monohull will be able to take rough weather a lot better which is why im leaning towards a monohull design now, and since i do want to do a lot of traveling i think sails are the best way to go.So you have made a final decision -- a sailing monohull -- is this correct? That's fine, but I still do not understand where "alternative propulsion" comes in on this type of boat, and alternative propulsion are the first two words you used when you created this thread. Can you explain your concept please?

[Psychobikerbill]

You may want to search for Stanley Myers patents. Interesting work in converting H2O into HHO (Brown's Gas) which is highly flammable. I have heard several reports of people running cars on it, although I have yet to try the conversion. Just a thought..

[spiel_mit_feuer]

for alternative propulsion i was thinking of adapting some alternative drive systems ive been working on and testing for cars, such as using a diesel generator to charge a small battery pack that works as a power buffer for operating an electric drive, it increases efficiency as the electric motors offer more torque at any range, this is something i was considering for a power boat, though i have no idea how much of an efficiency increase there would be since i havent tried it in a marine platform yet, it will increase a 50mpg to 200mpg on the road, so it might be worth trying... im also working on an efficient electrolyzer that can seperate hydrogen from water at a rapid rate, i could possibly use that to power a fuel cell for auxilery power on a sailboat, using either solar panels, or a wind turbine to power the electrolysis giving me free auxilery power for moving in and out of harbors, it would eliminate any need of buying fuel.. given the efficiency of fuel cells, and the electrolyzer, i still doubt it would be possible to power an engine directly as i dont think it could create enough hydrogen, so i doubt it would be useful in a power boat...though if i bought a small used planing hull i could probably run accurate tests

[spiel_mit_feuer]

psychobikerbill, the HHO systems, such as the design im working on could quite possibly run a car on hydrogen gas, im buying a small lawnmower engine for scaled tests soon, a fuel cell would be much more reliable than actually running it in an engine, so i could probably get a small planing hull and an appropriate sized hydrogen fuel cell to test it out in a marine platform, and since salt water is quite electrically conductive, i probably wouldnt need to use potassium hydroxide to increase conductivity of the water.. maybe ill build or buy an 18' bass boat to give it a try, seen them go for a couple hundred used near here for the hulls.. but i think displacement hulls will be a very, very long shot, so for testing hho i think ill stick with planing, hydrofoil, and multihulls.. multihull probably the best bet since planing and hydrofoils require a certain amount of speed till the displacement and resistance is lifted, could probably construct a small cat using metal drums for the hulls and see how that goes

[kach22i]

im also interested in higher tech style boat hulls such as hydrofoils, hover (im not sure that would be reliable enough though) and perhaps some ideas people may have that havent been built yet?.

You may wish to research SES (Surface Effect Ship) and Surface Effect Craft. You can start by using my user name in the advanced search function of this forum and SES or Hovercraft.

http://www.boatdesign.net/forums/showthread.php?t=15137&page=10&highlight=atlantic+hovercraft
Somewhere in this thread this design was mentioned, so I'm posting this here for future reference.

http://www.connormarine.com/pages/9/page9.html?refresh=1111977204133
http://www.connormarine.com/images/600_gt185rendering.JPG
http://www.connormarine.com/images/600_Untitled-1.psd.jpg

[kengrome]

for alternative propulsion i was thinking of adapting some alternative drive systems ive been working on and testing for cars, such as using a diesel generator to charge a small battery pack that works as a power buffer for operating an electric driveAnyone I've ever talked to says it's too inefficient to do this on a small boat, not to mention that the initial cost is several times higher than the use of a simple diesel marine engine driving the prop directly through a gearbox.

[boat fan]

for alternative propulsion i was thinking of adapting some alternative drive systems ive been working on and testing for cars, such as using a diesel generator to charge a small battery pack that works as a power buffer for operating an electric drive, it increases efficiency as the electric motors offer more torque at any range, this is something i was considering for a power boat, though i have no idea how much of an efficiency increase there would be since i havent tried it in a marine platform yet, it will increase a 50mpg to 200mpg on the road, so it might be worth trying... im also working on an efficient electrolyzer that can seperate hydrogen from water at a rapid rate, i could possibly use that to power a fuel cell for auxilery power on a sailboat, using either solar panels, or a wind turbine to power the electrolysis giving me free auxilery power for moving in and out of harbors, it would eliminate any need of buying fuel.. given the efficiency of fuel cells, and the electrolyzer, i still doubt it would be possible to power an engine directly as i dont think it could create enough hydrogen, so i doubt it would be useful in a power boat...though if i bought a small used planing hull i could probably run accurate tests


Running a diesel to run a generator to charge a battery bank is certainly NOT
all that efficient.

The losses resulting from converting the output of a diesel motor to stored electrical energy inside a storage vessel ( battery bank in this case ) could not be recovered , regardless of " more torque " of the any electric motor,let alone INCREASE the efficiency.I dearly wished it was otherwise , but it`s simply not , at least not at this point in time.

As Ken already mentioned , the cost is excessive also.

I commend you for trying.It would be great if someone does this.

[kengrome]

im buying a small lawnmower engine for scaled tests soon, a fuel cell would be much more reliable than actually running it in an engine, so i could probably get a small planing hull and an appropriate sized hydrogen fuel cell to test it out in a marine platformI suggest that you finish the alternative energy power system first, then measure its output. You may find that it puts out so little power that installing and testing it in a boat would be a complete waste of time.

[FAST FRED]

Most folks can get the highest level of efficiency by being able to accept two compromises.

A VERY! small diesel working at 80+% of cont rated power and at 90% of rated rpm will give the most range. Were talking 6 to 15HP here.

However there will be NO power reserve for powering into "the big ones" so its best on a well found sail boat.

And there will be NO power reserve (or tiny) for aux systems like battery charging, water makers etc.

You will still be able to have items like Hyd windlass as the entire engine power will be at the pump. with zero needed for propulsion.

The other compromise required is to operate under power at slow SL X .8 or max .9 .

If you can handle 4K or 5K on a 36ft lwl , 15-18 nm/g should be EZ and more depending on the quality of the installed gear & propeller.

FF

[spiel_mit_feuer]

i guess everyone here is suddenly an expert on engineering and physics and my years in college for it make me the least knowledgable on the subject

[FAST FRED]

"my years in college for it make me the least knowledgable on the subject"


Probably , while any "engineering student" may create an acceptable bridge , with a book,

The chances of someone outside any field , with zero practical experience , and not even a knowledge of recent Source material to go "cutting edge" is close to ZERO.

For boat designers and aircraft designers where a 10% improvement would be a MONUMENTAL life goal realized , the chances of someone inexperienced and unknowledgable getting beyond current efficiency is sorta slim.

The board , if your really lucky will keep you from blowing cash and time on dreams , and let you get out sailing .

When properly selected current tech will get the job done at low cost , repairable and even have a resale value , an amateur experiment may never have.

Good Luck in reaching your goal, whatever it is.

FF

[boat fan]

i guess everyone here is suddenly an expert on engineering and physics and my years in college for it make me the least knowledgable on the subject


I did engineering too , so what ?
I can`t do it.I openly admit it for all to see.
No one else seems to be able to either.

You certainly haven`t proven much, at least not here.
Oh yes , I forgot , your`e too busy calling people idiots.....

A true measure of efficiency has to include how much the
system costs , not just to run it , but to put it together in the first place.
How much more will it cost , and how much fuel would this buy ?

play_ with_ fire (as your forum user name translates from German)
is appropriate when looking at the expenses alone...

Theory is fine .But in the end it comes to this :

Show me your system , prove that it works ;)

[marshmat]

Show me your system , prove that it works
And that is the key to it all.

If anyone's interested in saving money on do-it-yourself alternative power, may I suggest the following:
1. Do a schematic diagram of your system
2. Buy an engineering thermodynamics textbook (I recommend Moran & Shapiro, but there are plenty more)
3. Read (2) and apply the chapters on the First Law and Second Law to (1)
4. If (3) didn't completely kill your enthusiasm for the plan, read the chapter on exergy analysis, then compare the cost of your system to the cost of the way we do it now.
5. If you've made it through the first 4 steps and haven't said "Aaahhhh... oops", you might have something worth investigating.

I should note that diesel-electric does come out ahead in this type of analysis in many cases- but not all. Large house load fractions and a wide range in target operating speeds tend to work in favour of D-E. For most yacht applications, KISS wins. "HHO gas", on-board electrolyzers, and all that other "free energy" stuff barely breaks even under the First Law, and completely falls apart under the Second Law.

Happy sailing.... wind is free after all. (If only the same could be said for sailcloth.)

[boat fan]

I will save myself a lot of trouble marshmat .
I admit that I found the " too hard ( read impossible ? ) basket " early
in the exercise.:) I think you know more about this than I do .

I also believe what you say. :D

[kengrome]

At first I thought this thread was going to be interesting, and I was willing to try to help steer spiel_mit_feuer in the right direction -- or at least in some direction since he seems to have none. But it seems he is also unwilling to demonstrate respect for the far more experienced and knowledgeable members of this forum ...

i wasnt planning to use sails on a hydrofoil (idiot)if anyone has anything positive to contribute to my post, then post if, if not, keep your mouth shut because i dont care to hear people who assume they know more than mei guess everyone here is suddenly an expert on engineering and physics and my years in college for it make me the least knowledgable on the subject


:mad::mad::mad::mad::mad::mad::mad::mad::mad::mad::mad::mad:


I'm not really surprised to see this type of behavior. Some colleges these days are very good at teaching recent grads how to disrespect their elders and other people with decades of practical experience -- people who actually know how things work in the real world, and from whom inexperienced college kids like this one might actually learn a thing or two.

But even if spiel_mit_feuer eventually stops talking about everything under the sun and gains some focus for a change, I think his piss-poor attitude will preclude his learning anything of value from the rest of us anyways -- and I will simply not tolerate any more of his caustic, condescending and disrespectful posts any more so I'm out of here.

[rivadezza]

you might be interesteed in maxpower engines, they make factory converted LPG engines www.65engineparts.com
Talk to Eric, he can help you to the best solution

[Psychobikerbill]

I have schematics for solid state electric generators, but I don't know how to post them here- HUGE pdf file. If anyone here is interested, I can try to e-mail them- just send me an e-mail at psychobikerbill@comcast.net and I will do anything I can to help.

[spiel_mit_feuer]

well kengrome, i refuse to show respect to someone who comes into my posts with nothing but negative things to say, he's done nothing but come onto my posts and just shit on everything, senior member or not, i dont give it a shit.. if he's just looking to start something he should go elsewhere because im not interested in his misplaced, misguided criticism, and his "its impossible to do something thats never been done" attitude

[spiel_mit_feuer]

riva, im not sure LPG would be a good idea, the efficiency would decrease and youre not getting any benefits on the price or availability of the fuel, i wouldnt even use that in a car, ill have to build a small pontoon boat/cat to test on, should make a decent fishing boat too :-D

[FAST FRED]

"its impossible to do something thats never been done" attitude

Especially with no background , no interest in learning from the current literature what the current "state of the Art" actually is , and certainly without bushel baskets of hard cash , and a few years of work.

Talking about the Desirements of an unobtainable (this decade) goal may be loads of fun , as Mental Masterbation.

But it sure doesn't get anyone closer to cruising.

YOU must decide what your interest in boating actually IS.

Underway, in a great boat operating as well as can be done after 5000 years of practical folks worked it out ,

or cursing the rotten luck that a modern efficient (in your eyes) boat cant push the envelope with out its weight in Gold being spent.

There is NO board that can create, for you , what doesn't yet exist , should you prefer to go cruising , in this lifetime.

Good Luck,

FF

[gosurfun]

If you spent a small amount of time doing a little research it would soon become apparent that diesel electric has been used for marine propulsion since about 1914. Submarines have used it and still do. You will not be the first or the last to use this method! Try listening to a lot of good free!!! advice, or prove everyone else wrong and go broke doing it.

[Psychobikerbill]

and since salt water is quite electrically conductive, i probably wouldnt need to use potassium hydroxide to increase conductivity of the water..

Everything I've read says that salt water is not a good idea- it gives off Chlorine gas.. I finally got to building one of these units and use baking soda. I just set it up on my van and it really helped with making more power and smoothing the engine out (yeah, yeah- a tune up would have done the same thing- I know :-) ) I have yet to take it out to check fuel economy.. Too bad I built too small of a unit to use as a sole fuel source- that will come along when I have the money. Wish me luck!

[Matt.D]

A water cell will give u 3 gases, If u can achive stage 3 production (Orgone)then u can use a very small amount to fersh water to go a long way! Loads more efficient than diesel but vert tempremental, not the best if ur half way across the Pacific. maybe then use ur electric motors then.
DONT USE SALT WATER it will destory ur cell!
Smaller call the better u dont want to be producing more of any gass then u need!!! A BIG BANG! out on the water wouldnt be good either! How many plates r u runing?
Best use some old style v8 car inboards they seem to run best
Matt D

[marshmat]

Matt,

What exactly are you talking about? Are you electrolyzing water?

Electrolyzing one mole of fresh water gives you one mole of hydrogen gas and half a mole of oxygen gas. If you're electrolyzing salt water, you'll get some chlorine gas too.

The energy you release by reacting the hydrogen and the oxygen- no matter how you react them- will always be less than the energy you had to put in to split the water apart in the first place. Hence why, in the context of "hydrogen economy" discussions, there is such an enormous emphasis on large-scale, distributed electricity production via wind, solar, etc. so that we would have an enormous supply of cheap electricity to make all this viable.

If, as has been mentioned earlier in the thread, you are trying to run an IC engine on hydrogen, you are getting into difficult and expensive territory. If you're trying to generate the hydrogen using electricity from the engine's alternator, and actually believe you are getting some benefit, then it's time to go back to basics and sit down with a book and a thermodynamics prof.

[Matt.D]

I think we r talking about 2 seperate cells here mate u r on the path of a hyd cell i was referring to a Joe cell. One water is charged (+tve) before u use it in the cell then no voltage is needed to induce Orgone Enegy out of the water so no u wont need to use the altenator. We r talking slightly beyond basic Thermodynamics. And a little in depth to explain in a few short sentencens. Google Joe Cell or visit u tube to view video.

[marshmat]

OK, so you're talking about a magical free energy device accumulating 'orgone energy' from the infamous 'luminiferous aether', generating an endothermic implosion which makes the engine levitate by antigravity. It doesn't consume any of its feed water, but somehow makes three gases appear out of nowhere. A few reports say that it doesn't work when "individuals with highly negative emotions or personality or character" are nearby. And the reason we don't see more of them is because the Illuminati and the Fabian Socialists are manipulating the top ranks of academia.

Because that's what comes up if you look for a "Joe cell" on the Web. And if you look for it in scientific literature.... well, nothing.

If a new technology is real, and works, then someone, somewhere, must have the test data to prove it. And if the people with these marvellous new ideas were serious about promoting them, that test data would be readily available. But what there is, is a closed, secretive community that is openly hostile to anyone who dares to ask how or why their mystery devices work.

So I come to the conclusion that it's bull, because nobody who actually seems to know what these devices do is willing to present any real evidence to the contrary.

[Matt.D]

Well if u say so mate! but i wouldnt believe it my self if i hadnt talked to him and seen it myself and now have a cell that has produced stage 3 for 2 months and 3 days now.
But hey, if uve worked it all out in 10mins of net surfing then the 30 odd cars driving around just south of the boarder here in oz must be all just rolling up and down hills on there own. And this is the bigest farse since cold fusion !
But keep reading basic thermodynamic books and then when ur done get out in the shed and start on so prac u will be suprized what u will learn with so hands on!
And instead of replying to this post with more quick whit perhaps try digging a little deeper into a lot of articals written on the topic they r realy not that hard to find.

[marshmat]

Matt,

I think that if someone has really found a new energy source, that would be a huge advancement for physics, engineering and economics. And I'd really like to find out more about just what is going on in these devices.

As a physicist, I am quite certain that there is a lot more to the universe than we understand at present. Indeed, the "normal" matter and "normal" energy we are familiar with are now known to comprise some 4% of the total universe. The rest, we don't know, and I have many friends who are working to improve our understanding of dark energy, dark matter, and whatever else makes up the remaining 96%.

Where I take issue with these so-called "free energy" devices is that people build them, claim that they work, claim that the reason they work is because of some mystical new energy, and then become openly hostile when anyone asks how they work, what this new energy is, where it comes from, etc. If it is a real, reproducible effect, it should be possible, through careful measurements with sufficiently accurate equipment, to determine how much energy is being produced, in what form. I have not been able to find any such information for any "free energy" device that is not self-contradictory.

I have even read claims that the "Joe cell" device draws on the telepathic energy of people near it, and will shut down if anyone with negative or skeptical emotions is nearby.

Our current scientific paradigm allows for new ideas, new explorations, and things that don't fit in with the current theory. I know a few folks who, a few years ago, blew a giant hole in the Standard Model and forced a major rewrite of a large part of subatomic particle physics. But to call for a change in the scientific paradigm requires accurate data and a feasible explanation for what is happening.

If anyone has an actual theory for how a "Joe cell" works, I will read it. But as a scientist, I expect to see strong evidence to substantiate strong claims.

So, if you can offer any information on what is really happening, I would love to see it. Who knows- you may be on to something revolutionary. But I'm not interested in unsubstantiated claims, and I doubt many others here are either.

[Matt.D]

Matt M, i couldnt agree more, the theroy of Orgone energy has been around for a while as for it being free energy, well technically its not as u have to charge the water first and ur using power to do that not to mention all the time and effort u put in and sometimes wasted ask anyone who has experimented with ant sicence project he will tell u that it always cost money.
Their is a lot of self contradictory info out there. that is if u read some of the articals written by a couple of would be proffesers down south and as for the quote that "negitive emotions kill the cell" well i havnt found that yet but i believe that its much likr the ouote " money doesnt buy happiness" spoken by the person that has none to justify not having any! I think the 'neg emotions" iis a get out of jail free card for not succeeding!
I dont agree with all that is spoken on the topic, i dont believe the joe is the inventer of the joe cell aas there is too many holes in the practice of his cell work to be the man behind it.
( hence why i perfer to referr to it as a water cell no a joe cell.)
and by reading some of the info out there then would be put off even trying to build one as just the water that is ment to be used is almost unitainable! There is no proff that it is an implostion either other then joes say so.

The only reason that i mentioned it in the first place was that "psychobikerbill" touched on the subject of hyd cell in his post and i thought he might have been trying to build a water cell.
Will keep u posted u may be a good bloke to bounce some theroys off.
Matt

[Tcubed]

The DIY electrolyzer which creates brown' s gas which then gets fed into the carburettor supposedly increasing MPG does at first glance seem to be a free lunch scam.

It takes energy to produce the gas and the energy returned by burning it must be less due to inevitable losses of any energy system.

But, what if it does actually improve MPG and there is actually more to it than meets the eye? Just speculating here, but is it at all possible burning HHO along with the Gasoline vapor makes the gasoline combust better?

I'm sure someone here can answer that and settle in my mind if there is any chance the claims made might be true.

[Matt.D]

Yes it does make for a better burn and when feed into the air intake ahead of the o2 senser ur ecu will adjust the fuel input accordingly and will give a better mpg but it is a little hard on the engine as the hyd. burns a lot faster and hotter, browns gas is not hyd. is is often refered to as "eithier" wich is one of the 3 by-prod gass of electrolises.

[divinesd]

Hybride Propulsion in combination with fuel-cell technology will increase propulsion with 10%. Unless you use air-conditioning you won't make it. Complete system saves approximately 40% of weight regarding a direct-diesel system. All these energy systems are calculated by Mastervolt, Victron etc etc.
Best tip I can give is; Save as much weight as possible, make sure you can go as fast as possible and limit your needs on equipment. For example: If you want to built a 30ft boat one can easily use an outboard for propulsion. Then you have no appendages on the hull. Charge your "gel" batteries with solar energy. But most important use a windarm for autopilot at open waters. I hope this all makes sense. :D

[kistinie]

Windvane pilot
Multihull is fast

up to what speed before getting lost you think ?


And honestly, never seen windvane pilot on a quick multihull and been told several times it wasn't adapted to fast boat with a lot of apparent wind...is it true ? , more info somewhere ?