An extra-heavy-displacement 11ft long Atlantic Proa for circumnavigation

[thecicada]

Gerry Spiess and Yankee Girl. I strongly suggest you read his book about his trips across the Atlantic and Pacific Oceans in his 3 meter sailboat. I remember he stopped to talk to a freighter mid-Atlantic, he had one hatch in the rear where he stuck his head out, he looked really rough! Yankee Girl is kept by the science museum in St. Paul, MN they might have more info on the boat.

[rhubstuff]

If this were a good idea, someone would have already tried it. Please do not disregard thousands of years of knowledge about boat design. This design will have a horrible motion at sea in all but dead calm weather. In spite of your calculations and opinions, it WILL roll, it will heave, it will pitch and yaw. And if it pitch poles or rolls over as you suggest it might, it will probably injure anyone inside. I don't know about other countries, but in the US, the Coast Guard may just determine this thing to be "manifestly unseaworthy" and refuse to allow it to go to sea, should you be lucky enough to drift into a US port. Most of the people posting comments for you could write a book on why this is a bad idea. Please don't subject anyone else, particularly someone you love, to a voyage on this vessel. Best to stick with what has been proven throughout years of seagoing history to work. You can't fool Mother Nature.

[swanpol]

Originally Posted by www.artis.guru

I am currently designing an extremely unconventional sailboat, which we as a couple hope to sail around the world, and if we are successful, that would also set a new Guinness World Record for circumnavigation in the smallest boat.

I have been thinking through a lot of things on my own, and I would like to ask you, all the knowledgeable and experienced people on here, if you might be interested to discuss this design and point out any possible problems and difficulties in it.

As you can see from the attached drawing, the design is technically an Atlantic Proa (the one which always keeps the outrigger to leeward), but unlike conventional multihulls, it has an extremely deep draft and heavy ballast.

Below are my main design considerations.

The main focus of the design is to build a seaworthy boat which would move in a pattern that would cause the minimum amount of sea-sickness possible. Due to my woman being quite prone to seasickness, I see seasickness as the highest of all the risks why our circumnavigation plans might fail. And because of that, we are happy to sacrifice many other things, such as speed, draft, conventionally acceptable looks etc.

Here is my train of thought:
1) The boat’s design has to minimise any rolling movements, as they are the component which makes the brain seasick. Straight up-and-down movements doesn’t matter, because our brain is perfectly accustomed to them, since it is the same kind of movement which our vestibular system gets when we walk.
2) In order to cut out the rolling movements, the hull must be mostly submerged, float vertically and have vertical walls, which eliminates any shape-stability and leaves the vessel with mostly vertical movement in waves (like a pencil with a lead attached to its end, floating vertically, 3/4 submerged). That means extremely deep draft compared to its length and beam. The inspiration came from R/P FLIP (https://en.m.wikipedia.org/wiki/RP_FLIP).
3) In order to have a vertical hull which is still manageable under sail and sculling oar (without engine), it has to be extremely short and narrow, in my case: the length of 3.5m (11.5 feet) and the main hull beam of 1.1m (3.6 feet), with a draft of 4.5 m (14.8 feet). This kind of crazy contraption would have a fully loaded displacement of 12,780kg (28,175 pounds).
4) In order for such a hull to be capable of carrying at least a modest amount of sail, I add to the hull an outrigger. But as I want the minimum possible roll movement induced by the breaking waves of the Southern Ocean, I put the outrigger only on the leeward side of the main hull (hence the Atlantic Proa). That way the bashing of the steep wave faces would be taken by the main hull’s vertical convex wall, and the hull would respond to it mostly by lifting up vertically through the wave, instead of rolling over to the side. The back of the wave is not as steep, therefore the leeward-outrigger-induced roll should be relatively small. But for it to be still tolerable, the ama should not stick out to leeward too far- just enough to enable the unstable hull to carry a modest sail area, enough for a slow cruising.
5) As one of my big concerns is if such a hull would sail enginelessly at least as close to the wind as the old square riggers did, I minimise the windage by having a small above-water volume (compared to the excessive underwater volume), which makes this boat to behave almost like a surfaced submarine. I also streamline the pointed hulls and outrigger, and I take advantage of the proa design and make the leeward sides of the hulls absolutely flat and vertical, which will maximise the lateral resistance, as well as giving a hydrodynamic lift towards the windward side.
6) I plan for an enormous amount of storage space and load carrying capacity in the deep bilge, enough for carrying 1 year’s worth of our provisions. With this heavy design I can afford it, and also it would give us a lot of wiggle room in terms of where and when we re-provision. That is especially important since I don’t expect such a boat’s speed to average more than about 2 knots.
7) The deep draft’s imposed limitation regarding shallow anchorages should be more than outweighed by the ability to anchor further out and in rolly anchorages, or simply staying heave-to in the open sea, while still having a pleasant living conditions aboard due to the lack of roll.
8) In order to maximise the living space on the very short boat, I make use of it’s deep draft and create many floors. As an added bonus, we also get an extra room with underwater windows (like in the concretesubmarine.com), which always stays pleasantly cool, even while becalmed in the middle of Indian Ocean.

What do you think about such a design? Does anyone of you have some experience with anything remotely similar to this? Or does anyone have enough theoretical knowledge and strong imagination to be able to predict how will such a boat behave herself?

Thank you in advance for all your thoughts and input, have a great day!

Artis,

BUILD IT, AND DO IT , THEN WE ,,,,,,

[Tillikum]

You might as well build it as a submarine since you won't be able to get out of the way of anything at 2.5 knots and diving to 50 feet or so will be your only chance to avoid shipping.

I'm afraid this particular exercise has probably long since reached its practicable limits. The ship in short, has sailed.

But if a paragraph in The Book of Records is your over-riding determination, maybe you could build an outrigger with the hull shaped like a bun and the "ama" shaped like a wiener and see if they'll let you in for the first half-made hot dog to sail the Atlantic?

Or maybe become a breatharian and see how long you can survive at the top of a telephone pole on just the nutrients in the eather?

It's a big book with lots of different records; there must be something more economical in time and money and less likely to lead to your mysterious and premature demise?

Though should you venture forth I'm sure it will make an interesting discussion thread here speculating on what was the cause of said demise.

[TrentePieds]

NewAlexandria:

I notice we have a "tillicum" among us.

You might like, as a Latvian, to know, that just like the Hanseatic League traded along the Baltic shores in medieval times, just so trading occurred on the west coast of North America in more recent times. The language used between the indigenous peoples - analogous to the medieval Baltic tribes - and the Georgian and Victorian English - analogous to the medieval Germans - was called Chinook, and in that language the word "tillicum" means "friend".

It is not to be expected that you would know about the canoe called Tillicum that in 1901-4 circumnavigated the world in command of Captain Johannes Voss, a German. Johannes, from Elmshorn just down the River Elbe from the famous deep sea port of Hamburg, was a REAL sailorman, who knew what he was doing because he had commanded "windjammers" over all the seven seas. He took Tillicum singlehanded around the dreaded Cape Horn.

I strongly suggest that you pay attention to all your tillicums in this forum, and stop insisting that you know better than they. Survival at sea does not depend on faith. It depends on competence. So far, you have not yet convinced us that you have competence either as a practical seafaring man or as a yacht designer. When you begin to put replicable, testable propositions before us rather than mere assertions, we may change our opinion in regard to your competence.

I, for one, hope that you will do so soon.

You may do so, exceptionally, in German, French, Spanish, Danish or Swedish - even Dutch or Afrikaans - rather English if one of those languages would suit you better than English. Lettish, however, is too esoteric for us, even for those among us who are comfortable in Russian. You'll have to forgive us for that :-)!

TrentePieds

[Lee Jerry]

Hey TP,

I'm a little confused. Did you post in the wrong thread, or just address the wrong member, or are you saying that NewAlexandria and artis are the same person, or other?

[TrentePieds]

Yeah - wrong thread :-)

While we are here, let me compliment you on your #107 in that other thread. Nice little refresher ! :-).

TP

[Dave9111]

Might be able to buy a used Steel Buoy and do the same thing. Just add a rudder. Somehow rig a big spinaker to it to drag you through the water.
Just hope the wind is going in the direction you want to travel.
The newer ones are usually equipped with solar and a power system and blinking lights. So you can save on navigation lights! When you want to go into harbor, just drop a huge anchor outside the port and they will think that they have a new navigation buoy!

[Skipper Kenny]

Originally Posted by carstenb

Ahhh who here remembers “The Flying Hawaiian”

These guys?
https://en.m.wikipedia.org/wiki/Hōkūleʻa

Only other options are the Urban Dictionary definition, and that is like something from a Jay & Silent Bob movie.

[Franziska]

Originally Posted by Skipper Kenny

These guys?
https://en.m.wikipedia.org/wiki/Hōkūleʻa

Only other options are the Urban Dictionary definition, and that is like something from a Jay & Silent Bob movie.

Nope. But this one:
https://www.cruisersforum.com/forums...ne-108559.html

[Franziska]

On a side note, have you thought about using a kite instead of a rig for propulsion?

There is a guy who crossed the Atlantic this way.

[TrentePieds]

I would think that if so, he'll want to do it from east to west.

Else where would the challenge be? :-)

TP

[Skipper Kenny]

Originally Posted by Franziska

Nope. But this one:
https://www.cruisersforum.com/forums...ne-108559.html

Thank you very much! 😊

[merrydolphin]

Um…………………..no. Makes no sense. Sounds like an oxymoron. An 11’ long 14’ deep Proa!?……………no. Find a better solution to seasickness. I don’t think that this is viable.

[Ike]

Well You have to give the OP credit for chutzpah. He already has 4 pages of replies (59) and counting on this forum, and 8 pages on boatdesign.net. https://www.boatdesign.net/threads/u...igation.68579/ Most which tell him it won't work for one reason or another, which I agree with. He will either be stopped by the Coast Guard, like the guy in the squirrel cage, or his wife will bolt and file for divorce unless he comes to his senses. Then again maybe he is just a troll trying to generate a lot of discussion.