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  #1  
Old 08-15-2011, 03:49 AM
ali3 ali3 is offline
 
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Smallest boat to sail ocean safely?

What would you consider the smallest size boat that could safely travel around the ocean?

Assuming of course the structural integrity of the boat is ideal for its size and form factor.
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Old 08-15-2011, 06:01 AM
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DennisRB DennisRB is offline
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About this big.

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Old 08-15-2011, 06:55 AM
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There are a lot of boats that folks have plied the oceans in, but frankly many of them aren't especially practical except for the record breaking attempt.

I was commissioned several years ago to design the smallest, practical ocean capable sailor, eventually designing an 18' gaff sloop. It has a full size V berth, porta-pottie, mini galley and a safe, self draining cockpit, which was enough room to stretch out and sleep in too.

Much smaller then this and you're into the "micro cruiser" category, which for coastal cruising isn't so bad, but for deep water work is just too little boat for the most part.

To be frank, you should go to sea in the biggest boat you can afford or handle. Being in an ocean storm, on a 15' boat, is like climbing into a blender and pushing the "what was I thinking" button. There's an old sailor's rule which is, never go to sea in a boat smaller the the seas you'll encounter. Trust me on this, you don't want to be in a 15' boat in a 16' sea, which is a fairly common occurrence in deep water.
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Old 08-15-2011, 08:03 AM
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ldigas ldigas is offline
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U-uh, this is one of those questions on which everyone will have their opinion, and there isn't really an answer.

Alain Bombard sailed across the Atlantic in an inflatable boat of 4.5 meters. I wouldn't call that safe though.
On the Mini Transat race sailors sail across in a 6.5 meter sailboats. Most of them survives

Practically, evetything above that is luxury

It really mostly depends on the skill and the personality of the crew. If you're (and I've misunderstood) asking what is the smallest boat that gets "ocean" class, that is regulated by the classification societies rules and so on ...



http://www.google.com/search?q=alain...w=1920&bih=971
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  #5  
Old 08-15-2011, 08:45 AM
ali3 ali3 is offline
 
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Thanks for answers guys. I have a few more questions though.

First off I can't imagine having 2 miles of chain for an anchor on board a vessel as small as I'm designing. Does an anchor have to touch the ocean floor to work or will it be fine just to cast one out on a boat this small? Do I really need one or is it fine to drift in open ocean so long as I have a compass for direction?

Also, how should a boat be constructed to avoid it being flipped over by strong waves? Since I'd like as much cabin space as possible I had a more "boxed" design in mind but I assume that something rounded like a speedboat would be better. For that reason the current design I have is a bit like so:

Code:
  .____.
 _|____|_.
|._______/
 \______/
Rounded on the bottom with the roof of the cabin boxed on top. It will be constructed of wood so as round as I can get the design.

@PAR
By 16' sea do you mean 16' deep? I was under the impression a majority of the sea is well over 1000' deep.
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Old 08-15-2011, 03:46 PM
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Ali3, the best thing you can do now is stop looking for a design. Yep, stop, you're nowhere near where you need to be, for an intelligent decision on this particular subject. What you need now is sailing experience, lots of it on all kinds of boats, especially in deep water when possible. With this experience comes a whole new list of things, you'll want and need in a design. This is a constantly evolving process and it's based on experience. The things you think you want now, will become quite silly when you look back in a few years.

I'm not trying to insult you, but based my recommendation on your questions and assumed understanding, of life at sea in a small craft. BTW, the average depth of the oceans (globally) is about 2.3 miles (over 12,000 feet). A 16' sea refers to the height of the sea and again, until you've been in a sea bigger then you are long, you don't know fear and difficult (to say the least) sailing.
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Old 08-15-2011, 05:32 PM
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Ali3,

I hate it when Par beats me to it.

But to reiterate. There are very small boats that are capable of safely doing an ocean crossing. But they tend to also be relatively expensive, often multiples the price of a larger boat that can also safely cross an ocean. An open 6.5 for instance in decent shape sells used for upwards of $60,000. Where I can think of any number of 35-40 foot boats that are also ocean capable for less than 30. So unless you have a specific justification for a small boat (records, racing class, ect) there really isn't a financial justification for going small. And small boats are much less comfortable than a large boat, and not necessarily easier to sail.

In addition to following Par's advice, either buy, or go to your local library and check out Chapman's http://www.amazon.com/Chapman-Piloti.../dp/0688148921 . Then read it through twice from cover to cover. It is without doubt the most informative book on seamanship, and while an expert might disagree with some of it's content, it is an exallent primer for new boaters ( I own 3 copies).
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  #8  
Old 08-15-2011, 06:25 PM
CatBuilder CatBuilder is offline
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The main thing (other than staying dry and upright) is being able to carry enough food and water to live for an ocean crossing. That's really the only requirement.

It's not about the size, exactly, when looking at very small boats.

It's about the ability to survive the crossing.

EDIT: Agree with PAR. Stop looking and start reading first.
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Old 08-15-2011, 06:42 PM
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I've often wondered why people want to go so small on ocean passages. I can understand the record attempts, but other wise . . .

I like to drink my beer rather then wear it, which is what you do in a small boat once off the continental shelf. Motion sickness will affect everyone, even the most seasoned skipper if it's violent enough. The smaller the boat, the faster the motion becomes so violent, that you can't do anything except hope you'll die quickly.

Do yourself a big favor and rent a boat. Take it into deep water and see if you can function for an afternoon. Make sure you eat lots of greasy food before you go and drink heavily in route. This will quickly show you what happens and since the boat is rented, someone else will have to clean up your multiple messes.
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  #10  
Old 08-15-2011, 10:17 PM
Submarine Tom Submarine Tom is offline
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Safely?

Quote:
Originally Posted by ali3 View Post
What would you consider the smallest size boat that could safely travel around the ocean?

Assuming of course the structural integrity of the boat is ideal for its size and form factor.
937 feet.

To better address your question: How do you define "safely"?

Actually, disregard that. Go sailing, it's the best advice you've received thus far on this thread.

-Tom
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Old 08-15-2011, 10:58 PM
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PAR put it about as succinctly as possible. Stop looking and go sailing. Learn first, dream later. During my 34 years with the US Coast Guard I lost count of the people the USCG pulled out of the Atlantic and Pacific who were doing what you want to do, but had no idea of what they were getting into.

The one I remember most clearly, because I was involved, was the Greek fellow who bought a 23 foot sailboat and was going to sail home from Cape May, New Jersey, USA to Greece. He had never sailed a boat and never been to sea. He did not have a clue. We talked him into selling the boat and buying a plane ticket.

Once you have gained some experience and learned "the ropes" (by the way that comes from the days of sailing ships) then you can think about doing it. By then you will have some idea of what is involved and what it's like to go out to sea in a tiny boat where you can't see over the next wave, let alone what's ahead of you.
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Old 08-15-2011, 11:27 PM
ali3 ali3 is offline
 
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@PAR & Stumble
I understand you're only trying to help. The reason for the smallest size possible is simply space restrictions. I don't have the means of building a huge boat and transporting it to the coast. The smaller it is, the easier it will be to store during construction and move upon completion.

Furthermore I think I confused most of you by using the word "sail" in the topic title. This will not be a sailboat. It's going to be more of a yacht/houseboat with hybrid battery/gas motors. Plenty of solar panels of course to charge the batteries and the gas is mostly an emergency reserve sort of thing.

@CatBuilder
I have plenty of compartments designed into my current drafts. Food storage won't be a problem.

@Submarine Tom
Well I wouldn't want my vessel thrown around by most the waves I'll encounter like a rag doll. Anything that can take a beating and not flip over so easy.

@Ike
I don't have the luxury of going on a dozen sailing expeditions to get my bearings. Having never maned or operated a boat, my plan is to take a couple of trips out on a one and a few free diving lessons. I intend to test out the ship in a few lakes and rivers before taking it to the ocean. Even then I'll make a series of short trips before anything over 1 week.

Thank you all for your advice.
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Old 08-15-2011, 11:56 PM
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Well then, one piece of advice, make sure you give a "float plan" to someone you trust and who will miss you, that can tell the USCG where to look for you. I am not being sarcastic. I am being serious.

First, a powerboat as small as you are talking about will not have the capacity to carry enough stores and fuel for an ocean crossing.

Second a "houseboat" would not survive offshore except on the most calm day. You should be looking at designs for offshore trawlers or cruisers. Definitely not houseboats.

Experience is not something to be lightly dismissed with a couple of trips. I know people who have been on boats all their life on inland waters, but would not consider going off shore without adequate training and experience. I have seen waves that washed the decks of ships over 300 feet long, and large sailing vessels who completely disappear between waves (yes you couldn't even see the top of the mast) Unless you have been out there in all kinds of weather you have no idea of what you are getting into. I have been offshore in a 26 foot open boat traveling from one ship to another, and it was awe inspiring, and that was on a fairly nice day with seas of about ten feet. Fortunately for me and the other half dozen person on board it was being operated by an experienced boat coxswain.

Quote:
Well I wouldn't want my vessel thrown around by most the waves I'll encounter like a rag doll. Anything that can take a beating and not flip over so easy.
Do you know how to do a stability analysis? If not you better have a naval architect take a look at your design.
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  #14  
Old 08-16-2011, 12:55 AM
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Again Ali3, do your self a big favor and take the free Power Squadron courses. Talk to the folks there, (who are only there to help) about your ideas. When the laughing stops, consider the investment in the few offshore courses they offer as well. Right now you're asking if you can preform an appendectomy on yourself and the answer is yes, but you literally haven't the faintest idea how to do it without bleeding to death during the attempt.

Trust me, once you get some sea time, you'll look back at the quality of these questions and comments from yourself and see them as the folly we do. Simply put, you are currently grossly naive about the realities of life aboard and at sea. You can learn this yourself, but it takes a long time. Conversely, if you'd like to speed this up a bit, you can take some offshore boat handling courses or beg rides in other peoples yachts.

Lastly, do some simple math and calculate how many gallons of fuel you'll need to travel from A to B in your wildest dream passage. With this number in hand, see how many ~15' boats can hold that much fuel. Frankly you could fill a 15' boat to the rails with fuel and still not have enough to cross the Atlantic, but what do I know.
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Old 08-16-2011, 02:41 AM
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Ali3,

I really hate repeating Par so I will add some specific issues I don't think you fully understand.

Your idea of an electric powerboat is not possible, and there are a number of threads here discussing it, but the short answer is that you need something like 100lbs of batteries for every lb of diesel they will replace. Now to do a trip across the Atlantic figure you need a range of 4,000 miles. A small boat will motor at about 4kn/hour. And burn about a gallon an hour on the engine. So to travel across the Atlantic you need to carry 1,000 gallons of fuel, which equates to around 7,000lbs of diesel fuel, to convert tht to batteries you would then have to carry 700,000lbs of diesel to replace the diesel fuel.

While these numbers seem ridiculous, just keep in mind that diesel has an energy density more than 100 times that of batteries. You could try to use solar panels to generate the power you need instead of using battery storage. But that same small motor is going to be something like a 10kw motor... Now if you are using 10kw/hr over 24 hours you will need to generate 240kw/hr over the course of the day for propulsion. Since most solar panels only generate for 8 hours in 24, you will need a solar panel rated at over 750kw to power your little engine.

In short it doesn't work, and solar panels don't help much. The only realistic way to cross oceans in a small boat (less than 25 foot) is under sail, or with a tremendous amount of money spent on a record breaker or some sort.

As for building a small boat because it is easier to transport... It costs a few thousand dollars to move a large boat by trailer. This likely wouldn't even cover the cost of the food for such an undertaking. It is a poor place to try and save money. In addition a small boat makes everything harder. Everything must be highly engineered and thought out because there is no room for error, or for extra gear to make life enjoyable.

I have a friend who races in the Open 6.5 circuit. When he leaves he has exactly one pair of shorts, and one shirt with him. He weighs the water on board, and the food, and the toothpaste. Because there just isn't room for extra anything. What you intend is a wonderful trip, and experience, but living through it should not be left up to chance.

Again please spend a few years (yes years) learning about how to approach this safely. Crossing an ocean on a small boat is an imminently dangerous activity, it can be done, but to do it safely is not even close to the same thing as taking even a week long cruise. It is a major undertaking and even life long sailors have been killed attempting it.
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