How small?

[dnf777]

While reading a book that is probably on every sailor's bookshelf, and needs no introduction, I began to wonder what the smallest reasonable boat to circumnavigate would be. Of course, the book would tell us that 36' 9" will do just fine, I'm wondering what are the main factors in deciding what size boat is safe. (of course, safe is a relative term!)

Is it sea-faring capabilities? Ability to carry provisions?
Speed and sail area both seem irrelevant as they are not related to size, per se, right? I'm thinking its the ability to carry provisions for extended portless legs?

Disclaimer: I have never accomplished an extended navigation...I only dream about it while working on a never-to-be-published memoir, "Sailing Alone Around Lake Arthur". Hell, we don't even have pirates in my book!! ;-) (you can see in my avatar exactly how far I've ventured from land)

[paulk]

Speed and sail area are totally relevant, since they ARE related to size. Carrying 500 tons of provisions in a barge with a too-small sail area isn't going to get you anywhere before your supplies run out. Everything in a boat is a compromise, especially on a long voyage. The books you read are details about the compromises that worked for one person or another. Someone sailed transatlantic in a 6' boat. You might not want to make those compromises.

[PCP]

I agree with Paulk. Assuming you are talking of doing it solo if we are talking about a modern light displacement boat, I would say 33ft, if we are talking about heavy displacement, I would say 27ft (I am thinking on the Vanguard 27 ).

[TQA]

Several sub 20 feet circumnavigations.

I like Shane Actons story see the book Shrimpy or read online.

Shane Acton was a sailor, known for circumnavigating the globe in an 18-foot (5.5 m) boat. He first set sail from Britain at the age of 25, in 1972.

Raised in Cambridge, England without any sailing experience he departed in a used 18' 4" bilge-keel sailing boat for which he paid £400 - not an enormous amount even in the early 1970s. The boat was a 'Caprice', a Robert Tucker design originally named 'Super Shrimp' but referred to by Shane simply as 'Shrimpy'. Later Shane was accompanied for much of the voyage by his girlfriend, a photographer from Switzerland, Iris Derungs, he sailed westabout through the Panama Canal, circling the globe and returning back to England as a local celebrity eight years later.

I had this book on board when I set off from the UK to go cruising, it often reassured me when I felt that I personally did not know enough about sailing or had a boat that was too small.

[Flybyknight]

Phoenix, a 27' Cape Dory just completed a circumnavigation.
If interested, you may find a wealth of information on the Cape Dory web site.

Dick

[dhays]

Originally Posted by dnf777

Speed and sail area both seem irrelevant as they are not related to size, per se, right? I'm thinking its the ability to carry provisions for extended portless legs?

I'm most likely much more ignorant of this than you. However, it seems to me that size would related to speed, which would be very important when planning any type of crossing. I seem to remember that hull speed is a factor of the square root of waterline length. So the longer the waterline, the greater the potential speed for the boat. I'm guessing that is technically true only for displacement hulls but still has got to be close for lighter displacement hulls like many cruisers.

Anyway, I think the difference between say an 8 knot hullspeed vs a 6 knot hullspeed could be hugely important when looking at an ocean crossing. It would effect not only provisions, but weather planning as well I would guess.

BUT! I've never done it so I'm just guessing/asking for information here.

Dave

[Boasun]

The size of the vessel and what you desire to eat helps determine whether you are going straight around the world with no stops, or that you want to stop in various countries and explore their culture and making new friends along the way.
Around the world with no stops; A lot of MREs & an ocassional fish.
Stopping in far away places with exotic names; Interesting cousines and liquid refreshments. Plus meeting new friends.

[CapTim]

Sadly, the boat length is rarely the limiting factor for boat speed. Wind is usually the problem. Unless you get into planing boats that can really take advantage of high-wind days (and thus push the average up) a boat rarely averages it's hull speed. Heck, if a boat can average half it's hull speed on a passage, that's a good deal. Of course, using an engine will help, but then, you aren't sailing anymore, you are motoring. Which is expensive, and now you need big tanks to hold all the fuel.


Consider this: A 'normal' non-stop circumnavigation can be expected to take about 225 to 250 days on a designed-for-purpose boat. (there are boats that go a lot faster, and boats that go a lot slower, but that's a solid middle-range number).

A circumnavigation is going to be in the range of 24000 to 26000 miles (yeah, I know that's not the diameter of the planet, but nobody sails on the equator.. there's some land in the way).

Anyway, granting that these are rough numbers, you are looking at around 110 to 120 miles per day. That's about 5 knots.

Jessica Watson just circumnavigated in a 34 foot boat with a hull speed of about 6.5 knots. Took her 210 days, and her route was 23000 miles, giving her an average speed of 4.5 knots. So she averaged a little more than 2/3 her hull speed. (I use those numbers because I don't have to reach very far to get them.. other people have circumnavigated non-stop, but few with as much publicity as she got, so the numbers are easy to find)

Of course, as you know, speed is just one of a few thousand considerations. For me, cost is a huge one. And going from a 30 foot boat to a 40 foot boat more than doubles the cost of the boat. going from a 20 to a 30 foot boat doubles the cost. Doesn't take long to feel like a low to mid 30's boat is pretty sexah...

Also, bigger boats need bigger lines, bigger sails, bigger deck hardware, bigger paint jobs, bigger hauling fees, bigger engines and fuel tanks, bigger crews, bigger slip and slip fees, ...

Also, the NorSea 27 has at least 4 boats in it's ranks that have circumnavigated. For what that's worth.

[pontiakos]

THE MIGHTY FLICKA...many roundtrips....20ft long, one of the post wood modern legends. Built by Pacific Seacraft

[nemier]

DNF777,
I have pondered this question myself now for at least two years, 24 hours a day, 7 days a week. I have 'considered' the question for last 30 years...
My personal conclusion for single handing...
28' Bristol Channel Cutter - minimum.
34' Van De Stadt - optimum.
40' J-boat - luxury.

32' would be fine, but compromises will have to be made...fuel, water. food, etc, but you know that already...
I think it's more down to the specific compromises you are prepared to make, rather than the particular vessel. Most vessels can do it, but can you define the compromises you are prepared to make?