Unusual design for an extra-heavy-displacement 11ft long Atlantic Proa for circumnavigation

[CarlosK2]

Small, light sailboats (D/L = 150) with a wide beam (LWL = 2.5 Beam) have a downwind behavior reminiscent of a catamaran. 'Semi-displacement / semi-planing' speeds (0.40-0.80 Froude) reduce the movements of a small, wide beam sailboat. I mean that sailing slowly or very slowly is not as easy as it seems because it can be very uncomfortable, and the other way around: a reasonable speed as a starting point (e.g. 0.50 Froude) can be a good starting point.

 

[kerosene]

Well I am glad we got an active thread. Too bad that it was another “I have never sailed and want to start with a circumnavigation, I have also never owned a boat but will design my own and will totally rethink it all. And all who point out flaws are just negative and closed minded.” -type of a thread.

 

[comfisherman]

Intersection phenomenon, wonder if it's cultural that high engagement only happens in the negative.

 

[Milehog]

After thousands of years of refinements boats have evolved common characteristics.
This has been considered, no?

Orbital motion of water molecules in waves.
This has been considered, no?

A boat deeper than it is long will have unconventional handling.
This has been considered, no?
Oh wait, it is the whole point!

Happy April Fool's Day!

 

[Noah Stone]

Let's say you are able to create this, this is my train of thought:
1)How are you supposed to avoid storms, I would think you are so much better making a racing trimaran that can outrun any bad weather, and due to the calm seas, it would be on you wouldn't get seasick.
2)Its the same length as an international moth and moths' characteristics are completely change by move around the vessel which could be detrimental if the boat did work
3)There's no space for an engine powerful in a boat that size for any emergencies or even just motor sailing so you're not in an ocean crossing for half a year.
4)If you ever go through warm water the inside of the boat could reach incredibly uncomfortable temperature and humidity levels, this already happens to metal boats but yours would be exaggerated cause there's no open galley or large enough deck to hang out on for days on end
5)Why 11 feet? Boats around this length are great for mobility but not living aboard for long times.
6)There's a reason the smallest boats you could do ocean crossings comfortably and safely are around 30 feet
7) In the absolute best case this boat will be about as stable as a mini 650 and probably less space, go sail one if you can and see what you think
8)Boat projects are always more expensive than you think, please get a fun sailboat to sail around on the weekends, and if its nice enough weather even take your wife

 

[BlueBell]

Easy there folks, we lost Artis over a week ago.
Hopefully he's busy building in order to prove us all wrong.

 

[peterAustralia]

maybe we were not nice enough to him,,, It also occurred to me, this thing would be so unmanouverable,, that it would be nigh impossible to get out of the way of a cargo ship on a collision course, my 2 cents was top speed was 0.5 knots, but I think that is generous,, realistically maybe 500 meters an hour.. hard to get out the way of an approaching ship,, also at say 5 meters depth, there is 5 tonnes of force on every square meter of the hull,, suddenly you have to be pretty sure your detailed design is correct, scantlings, frames, stringers etc

 

[comfisherman]

Honest question, what's the best way to politely tell someone they are having a really bad idea? That functionally all the aspects of the idea are fundamentally flawed?

 

[bajansailor]

Honest question, what's the best way to politely tell someone they are having a really bad idea? That functionally all the aspects of the idea are fundamentally flawed?

By offering comments like the hundred odd above?
Artis hasn't been seen on here for a week - I guess he took note, and probably decided to bail out rather than trying to further argue his case.

 

[wet feet]

I hope that is the case.Or alternatively,that he calculated just the cost of materials and labour for the project and is now looking for "normal" boats in that price category.There are thousands of them for sale all over the world.

 

[comfisherman]

By offering comments like the hundred odd above?
Artis hasn't been seen on here for a week - I guess he took note, and probably decided to bail out rather than trying to further argue his case.

I guess that's more or less my point. It was four pages of fairly diplomatic replies to an idea that was more cartoon than plausible. Makes it hard to accept the notion that we were some how unkind.


Story for another time, but we had someone locally spend 2mil and 15 months to make what is arguably one of the worst designed boats of its kind in the last 30 years.

Sometimes orientation to reality is the kindest message.

 

[bajansailor]

Story for another time, but we had someone locally spend 2mil and 15 months to make what is arguably one of the worst designed boats of its kind in the last 30 years.

I remember reading about a motor yacht based on a trawler hull that capsized when it was launched down the slipway, and I was wondering if you were referring to this one - but when I googled it, it is a 10 million $$ yacht.....

 

[Milehog]

That yacht was a cautionary tale of bad management, lack of communication and general poor judgement.
There is likely a thread on it here somewhere.

 

[sharpii2]

Small, light sailboats (D/L = 150) with a wide beam (LWL = 2.5 Beam) have a downwind behavior reminiscent of a catamaran. 'Semi-displacement / semi-planing' speeds (0.40-0.80 Froude) reduce the movements of a small, wide beam sailboat. I mean that sailing slowly or very slowly is not as easy as it seems because it can be very uncomfortable, and the other way around: a reasonable speed as a starting point (e.g. 0.50 Froude) can be a good starting point.

I used to have an extreme prejudice against sailing fast. I am starting to grow out of it.

But there are practical matters. Such as, how do you get the boat to steer itself when you aren't at the helm? I suppose, in this case, an electric autopilot is used. Now, it needs a reliable power source. I suppose the better batteries available these days plus better soloar panels can take care of that. If not, then a gen set is needed.

Also, there is the matter of weight. Nowadays, it is possible to make very strong, rigid structures that don't weigh a lot. But such can be pricey. Yrvind has spent untold amounts on his heavy, little schooner, made of foam sandwitch, epoxy, and lots of carbon fiber. All of this for something that will likely make just one voyage.

Sorry for getting off track. I just had to get this out.

But another problem with light weight is limited carrying capacity. For an athlete who just wants to sail fast, no problem. Just load minimal back-packing gear and very expensive freeze-dried rations.

As for water?

Just take the minimum amount. Maybe 1 liter per day, maybe 2. And you can get a manually powered water-maker. But I hear those are pricey, too.

As for ultimate seaworthiness?

just have a very deep, wing-like keel, with all the ballast near the bottom of it. Just hope it doesn't find a way to break off in the middle of a rough sailing day--or night. With the extreme initial stability of the hull, and the ballast very far from it, there will be plenty of wrenching on it, as the hull tries to conform to the surface its sailing on, and the keel ballast tries to stay put. I suppose this can be engineered around. I've notice not very many stories of canting ballast keels falling off. In the '98 Around-Alone race, one had a severe ground strike, but made it to port. The poor fellow was out of the race, but the nearly totally destroyed system still kept the heavy end attached to the boat.

In the video, the sailing doesn't look all that rough, even in the conditions that are rather rough. Impressive. But I suppose he is sailing downwind. Sailing upwind may be a different story.

But the point is made. Most voyaging is planned around sailing mostly downwind.

 

[sharpii2]

I remember reading about a motor yacht based on a trawler hull that capsized when it was launched down the slipway, and I was wondering if you were referring to this one - but when I googled it, it is a 10 million $$ yacht.....

Oh no!

Looks like someone didn't do their weight study and meta center calculations.