Small Tri's under 20', any mention of foils is banned..

Planing

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I'm not all that convinced that an ultra narrow waterplane is all that important on a small trimaran if you're willing to power it up with enough beam and SA so that it planes easily in lightish wind. The Weta is a good example of a planing main hull-I think its L/B is about 6.6/1. My 20 footer in 1971 was slightly narrower than that and was a blast to sail. My 14 footer back then was 7/1. The planing hull opens up room in any size tri if only for a cooler or?

 

Interesting, the Horstman Roomerans are about 8:1

 

And yes, why would you want 6 berths in a 24' ?
Far better to design more space and utility for 2 with an occasional berth in the bow perhaps.
I'm really keen to have a closer look at this Patterson 21'

 

I've got 6+ berths on a 37' and haven't needed them all yet....but you never know...
daysailing with 14 the deck is still uncrowded, size matters...

The planing hull with ama approach is interesting. Check out the soling/ tri conversion threads to see if it seems worthwhile.

As a example,the old Venture 21 was a planing uldb that had some racing success and could hit speeds in the teens downwind in a breeze with enough sail up. The keel weighed 400-500 pounds, if you could bring the amas and beams in for that weight it would still sit on ts lines but would need a stronger mast, rigging etc but be faster upwind and reaching because it would stand up to the sail area.

Chances are 4 guys in a Aussie skiff going for it will blow past you but couldn't be counted on to get the kids to the picnic.....

For beach cruising the under 20 size seems more like a canoe, kayak or longboat, if the hull gets too big it won't row or paddle well, the planing hull gets harder to live with there.

 

Here's a beauty and available as a plywood CNC cut kit but sadly out of our size range, the M80. Anyone know it?.
http://trimarankit.com/trimaran-plywood-kit

 

We'll have to start the 25' trimaran thread....

On the wide planing hull speed to windward starts getting limited to hull speed the wider you go as well as having more motion over the waves.. The slender hulls can push past that barrier more easily, really a matter of picking the compromises that suit your needs.

 

Remember the context. I was talking about sailing small multihulls with a small family.

It may be that, like my parents, there are 2 adults and 4 children, all of whom are keen sailors (OK my Mum would go along for the ride, not actually steer the boat) yet wanted a cruising boat. Seems like none of you were bought up like that. 5 of us cruised our Mirror dinghy in Sweden and France (my sister chickened out, but we did take our dog with us on board)

And check my 23yr old Wizard and Sango designs, or my 30 year old Merlin, all of which have potentially 6 berths. None are slow boats - the Merlin won "Fastest Dutch multihull" two years in a row. We overtook 8m Dragonflies off wind in our Wizard.

And if you check the Wizard page you will see it sailing with 6 adults plus a baby. And how about this photo of 20 people on a Sango??

And this report from a Sango owner "I've also had a couple of adults use one hull as their accommodation for a 10 day trip. 5 adults have slept on board and have squeezed 7 adults and children into the cuddy for dinner"

And from another "It is a little quicker than a Farrier 9a, at least the ones in Adelaide. Best speed so far 22.6 knots. I have a photo of it on the gps. "

Way off topic, sorry, but I do not make claims I cannot prove.

Richard Woods

 

I actually did grow up like that Richard...5 people on a 23' monohull....and thank the stars I could sail off alone at anchor in the dinghy, (they used mine).

I've been reading Technomad Steven K. Roberts book "From Behemoth to Microship" He undertook cross country bike rides on huge contraptions weighing hundreds of pounds loaded with computer gear.....then started trying to integrate this approach to boats, specifically small trimarans. It is often hilarious but it is kind of a cautionary tale. He abandoned a 30' folder project with a 10' wall of gear as too big then went on to eventually scaling back to the 20' range, still with loads of gizmos. Currently he is outfitting a large mono for world cruising but I wonder if building the better mousetraps is where the fun lies.

The smaller the envelope the less you can bring but what people "need" on boats these days is boggling. I am amazed at 5 ton lists of basic necessities on catamaran cruising threads. If sailing is the goal less is more, yes I can see the bunks being needed for an event etc....but actual cruising is happier if everyone has space, something multihulls are good at. KISS is especially important for small less is more sailing.

 

I've met Steve a few times, an "interesting" guy

As I said elsewhere, since Sept I have lived with only "carry on" baggage, that includes clothes, computers (2), camera etc

RW

 

My boat electronics are a antique GPS, compass, leadline and VHF used with my paper charts. Of course I have to bring a battery amp for my violin but a guy needs to practice.....Steve wouldn't make it, one lap top and cell is the personal limit.

 

Not doubting your claims Richard. Love your work.

 

I've got a bit behind on this thread so catching up, the Patterson 21 Tri has mentioned by Red if I remember correctly. It's hard to get any information on this boat, but DL made a comment;

I think you're very wrong about the Paterson 21-it's one of the most innovative designs around with more room than most 21-22 footers.
It's designed with a wing mast and the clean lines give it great aerodynamics. I bet it sails very well and would "charm" a small family including the kids.

Can you please elaborate DL. You seem to know more about this design and I'd like more info on it.

Thanks

 

Guy's ,
Discussion here seems to be heading in a direction of 20 footers with accommodation. At the complete other end of the spectrum would something like this fit the bill as the ultimate 20 footer?

http://www.duckworksbbs.com/plans/smoot/slingshot19/index.htm

 

I'm not sure I'd actually enjoy owning a yacht as simple as that, you'd have to have a very specific objective in mind.

20' to me means an open sports day sailor, I've come to the conclusion for cruising you need to be at 23-24 foot which allows a lot more internal volume.

 

So are we all slowly realising that we can't have a dual purpose 20 footer then.

If we beam up the centre hull to take the loading of a couple of adults and say two small children, we end up with a relatively slow boat, yes if you increase the sail area and beam you are able to get the boat to plane, but at what practical cost, managing very large powerful sails which need constant reefing and adjustment and a constant management of the boat with its wide beams and potential for pitch poling over the Ama when that powerful main suddenly isn't managed correctly. That sounds a recipe for a family disaster.

On the other hand lets go the other type then, the fast daysailor. Who would sail that type of boat. Probably ex cat sailors looking for fast sailing not in a cat, that he can race with one other and that can carry kids and one other adult perhaps on day sailing excursions. To carry that broad sailing weight the hull beam has to be wide and yet the boat powerful enough to be sporty. OK we are back to large sails and wider beams meaning a poor handicap rating which would be uncompetitive in mixed multihull racing.

But thats not to say you couldn't have a racing suite of sails and a family day sailing suite, but then the cost is rising. Simple reefing maybe enough perhaps but then there's nothing like a well set mainsail with a fast boat that feels just right. Reefed down mains all of the time, just aint gonner give that thrill I'm afraid.