Little Catamarans Vs. Little Trimarans for Beachcamping

Discussion in 'Multihulls' started by rayaldridge, Aug 17, 2008.

  1. rayaldridge
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    rayaldridge Senior Member

    I have a different point of view: that one is always better than the other, mainly because one is always different from the other, which implies a difference in goodness as well. If some boats are not better than other boats, what reason is there to draw new boats?

  2. uncookedlentil
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    uncookedlentil Junior Member

    beach camping multihulls

    One thing I wonder about human-powered tris is that if you have side nets, where do you paddle?

    Tramps can be managed by mainsail slugs and a couple of continuous loops for and aft on the tramp if you're rowing a tri, or in the case of paddling couples, the tramp could be left permanent between beams and sliding hatches for and aft give normal paddling stations, ends are for lite stowage anyway due to avoiding pitching problems.

    The first person I met at a long ago wooden boat show was a slender woman who had just finished rowing a dory to Alaska and back during the summer.
    Due to her sliding seat, she was able to stay comfortable in even the breeziest weather whereas her kayak partner was continually having to dress up and down.

    she also grumped about the racing kayak's ability to keep up and it ended up being her responsibility to set up camp every nite while waiting for him to get caught up and regain the use of his legs. :)
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  3. dsuursoo
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    dsuursoo Senior Member

    as i said, i paddle from back aft. you know, behind the side nets.

    ray, i notice you're more or less sold on your cat being 'the best', and for a lot of people, yeah, that's what they're going to want.

    me, i like what i've got on the drawing board now. lean, fast, unsinkable(unless i really screw up), able to field a massive sail area to take advantage of even tiny breezes, single-handed by design rather than modification, light, trailerable without any fuss, and still features storage to go a thousand miles without stopping(except maybe for water if i don't feel like evaporating my own)

    and you know what? it's a tri. yes, that slider sure does look fun, but it's not the boat i need, because it doesn't fit what i want to do. in other words, not the best for me. that doesn't make it better than my tri, it's not worse, either. it's just not what i need. it's not that one boat is better than another, it's that it's more suited to a particular task.

    but i will say, the surest way to not win anyone over to a viewpoint is to beat them in the face repeatedly with it.
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  4. northerncat
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    northerncat Senior Member

    love the look of the small osram, wonder if it wont be too heavy for the size though?
  5. rayaldridge
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    rayaldridge Senior Member

    Sure. My contention is not that tiny cats are better than tiny tris in all ways. It's that (I believe) they're better for a specific narrow purpose-- beachcruising. It's sometimes difficult to argue the point, however, when there are so few cats like Slider for comparison purposes. Most folks have never seen one. It was, I can tell you, even harder to argue the point before Slider existed, because it was sometimes impossible to get people to even imagine a cat like Slider. A lot of folks told me that if a boat like that was such a great idea, someone else would have already built one.

    Your tri sounds fine to me, and has many advantages over Slider. Sorry if I'm overenthusiastic in my advocacy. I think there's a natural tendency to love a boat you've built, even more likely when it's a boat you designed-- and almost irresistable when you've been told a thousand times that the idea behind the boat was stupid.

    When the boat in question turns out great, there's a strong motivation to spread the word. Much of the impetus for the design came from my observation that there were plenty of little tris that were more or less suitable for beachcruising (have you seen the videos Jim Brown made on camping in Baja with Windriders?) This seemed strange to me, because in larger sizes, there seemed to be a widely-held belief that cats are more comfortable than tris for cruising-- though I know not everyone feels this way. It struck me that this should be even more defensible a viewpoint in the smallest sizes, at least on the basis of comfort-- but no one appeared to think this way but me. Or at least, if anyone felt the same way, they haven't translated those feelings into a boat.

  6. dsuursoo
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    dsuursoo Senior Member

    heh, i don't know if thirty feet is 'tiny'.

    and i'll agree that it's hard to not shout the praises of something that's yours, from idea to sailing, all the way. i've felt that way more than once, i totally understand being excited about the slider(and i have to say, it's actually rather put together. not exactly what i myself need, but it'll fulfill a suprisingly wide selection of people's needs).

    and it's true, when you get down to the 'pack it in the back of the truck/on top of the car', zip about the shore, have fun with it for a day or two, a little ten or fifteen foot, trampoline top tri is going to be more stable, that's inherent. cats match tris for stability once you get up above probably about 20-30 feet, when you're building for performance. the slider's not really about that, but i'm sure it gets up a good turn under the right conditions.

    but then, when you're at that point, a cat has the advantage of simplicity. one less hull, and a bit less weight(which is also a disadvantage), and that can come with an easier takedown/setup.

    but the trimaran's greater weight comes with advantages.

    more stability-i've seen(and been on) beachcats that would capsize on the beam in high winds when i was a teenager in hawaii. it happens fast in a cat, thanks to that trampoline in the middle. netting eliminates this, really, but then it's not too comfortable to sail on. trimarans have the advantage because of the weight of the center hull, and the slots created by the trampoline meeting that hull. it gives you the time to get to the windward side, as well as dumping the lifting air.

    more displacement- yes, the slider's got a fair bit of capacity, all told. 600 pounds of design payload is pretty good. but in a little cat, there's only so much displacement before you're swamped. trimarans in the same size class(remember, 15-foot trampoline top) will generally have more displacement, with a corresponding increase in capacity.

    but cats have their own advantages in the same size class.

    weight- this can, in the small cats, often make for great performance under sail. not always matching the trimarans, because of the greater drag imposed by greater wetted surface(that damnable displacement again), but it also makes for something easier to get up and down the beach, even by yourself(as a note, my own tri is going to be a bit of a bear. i can drag that sort of weight around, but it's not easy).

    greater crew space- in a trampoline top, the cat has its connecting struts generally further spread apart than a trimaran. this tends to add extra space for the crew to move on, and work from. some tris make up for this with fore and aft nets, but it's generally not the same thing. as a note, in my own trimaran, i'm not planning on either, i know i'm giving up some space, but i can live with that.

    but once you get above a certain minimum size(i haven't quite got that nailed down, but it's at least 20-25 feet), catamaran and trimaran advantages and disadvantages tend to more or less cancel out, and things become much more of a preference thing entirely.

    but as it's always said, it's based entirely on what you need/want to get out of your design. in mine, i want speed and stability, single-handed crewing, and generous capacity and unsinkabiltity.

    but you've got some comfort advantages that i won't have, in the slider. and that's a plus. if it gets snotty out, or if i'm open ocean sailing, i'm probably going to need a drysuit. that, and what looks like rather reasonable(some would call it tame) handling, and a very simple catboat sailplan are some very strong points to the slider. as far as taking the family and small kids out, it's well thought out.

    but i myself wouldn't take it on open ocean trips(at least, anything more than a few hours), or on endurance races. that's more where my own will come in very handy. between a hull that's primarily given over to displacement(almost totally sealed, save for storage sections), outriggers that are intended for low drag when submerged, and a very fine L/B ratio(about 13-1 for the main hull when loaded, closer to 20-1 for the outriggers), and a shallow draft, kick up rudder and centerboards, and reasonably light in weight. yeah, i'm building an endurance racer and adventure boat. you've built(and quite well) a family daytripper.

    much different parameters really.

    but the above, discussing small beachboats is my own perspective on the debate.
  7. rayaldridge
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    rayaldridge Senior Member

    You're right-- they are very different parameters. Your boat sounds very interesting. That's going to be a speedburner. Do you plan to race her in the EC?

    I'd have to disagree that many 16 foot tris will have more displacement available than Slider. Most of the little tris have quite a bit less, especially if they have fine hulls. I suppose this is because a cat can divide its displacement between two hulls and a tri must carry it all in one. A tri has to be longer to have the same displacement and the same hull fineness as a cat of similar displacement, and this is true all the way up the scale. Farrier's tris are something of an exception to this rule; he uses fatter hulls than most tri designers.

    I'm no expert boatbuilder, and I used southern yellow pine for my solid timber and a relatively heavy plywood for planking. A good boatbuilder ought to be able to get Slider's weight down below 400 lbs. But even at 500 lbs lightship weight, that's 600 lbs of capacity. Compare that to the Windrider 16's 500 lbs (and that's pretty optimistic-- the sales brochures say it's ideal for an adult and a child.) Slider can handle overloading a lot better than a lot of little multis, too, because of her flared hulls and substantial freeboard. A Windrider 16 with 500 lbs on it will be riding mighty low in the water-- imagine a couple of big fat guys on one and you get the picture.

    I'd have to disagree with your description of Slider as a family daytripper, since she was built as an open cruising boat for two. Almost every aspect of her design embodies the idea of overnight trips. For example, she has a slat center deck of cedar, because that's more comfortable for sleeping on than a tramp, at least for two people. Two people on a tramp tend to roll downhill to the center, where they jam up against each other. The deck is heavier than a tramp, but I accepted the weight so that she would be more useful as a cruiser. Another example is the dry storage under the forward decks-- open would have been lighter, but less suitable to cruising. The modest rig is a concession to cruising. It's fun to go fast, but not much fun to capsize when you have a lot of important and expensive gear aboard. Had Slider been designed as a daysailer, I'd have put a bigger rig on her. For daysailing, it's okay to spend an afternoon with your hands on the sheets. For cruising, not so much. I want to be able to cleat off my sheets in good weather. Slider's hulls are many times more buoyant than any beach cat's so if she goes over, you won't be able to right her without help.


  8. dsuursoo
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    dsuursoo Senior Member

    if you're referring to the everglades challenge- i wish! that'd be a blast. and since the total boat weight, with rigging, no payload, no rider, should come in at ~450lbs or so, but probably scare the hell out of 500. i'm thinking that's about it, maybe a touch heavier. but, being in seattle, it's a bit of a long trip, but i could always take it down through panama....:D

    hm. i always built my outriggers for a fair bit of bouyancy, when i was making beach tris when i were a young guy trying to impress girls with my sailing. so maybe it was personal design that led to tris with more displacement capacity.

    and i can see how you got a fairly high weight on the slider, you really built that puppy to last, huh? talk about heavy construction... i'm going to use primarily 4 and six millimeter ply, with fiberglass for strength. thusly the light weight.

    and yes, the slider does have some generous capacity, so for overnighting, yes, definetly fits that bill. i suppose my estimation of it as a daytripper is based on size and rig, since i didn't know quite enough about the construction.

    hm. do you have any sealed bouyancy in the slider? that was one of my large design requirements for my tri(thinking of calling it 'immigrant son'-if you know your classic rock, you'll get the joke), having unfloodable sections. in the main hull alone i've got close to 30 cubic feet(without the plans on hand it's hard to say, could be as low as 20) of sealed airtight space, that i might also use an expanded foam on. so i've got somewhere in the vicinity of 1500 pounds of displacement that i can never overcome. i've done this before in a boat, a catamaran actually, and we had the hulls totally under, and the trampoline more or less awash, and still creeped it home. i'm hoping to have at least 15 cubic feet of volume that can't be flooded in the outriggers as well.

    i do know that a outrigger of the dimensions i use displaces somewhere around 1600 pounds of water, in salt. so hopefully, i'm going to have plenty of capacity, and add to that the unsinkable factor i'm trying to build in. that sealed displacement i talked about is going to be divided into subsections independent of each other-it's actually one of the reasons it's going to weigh in at 400+ pounds. but unless i smash it to bits on a cliff, i'm gonna be able to come home, even if i have to disconnect the outriggers and turn those into a catamaran and get home on that. a fun note about those outriggers- i'm putting a fair bit of tumblehome on them, so they'll hopefully be low drag if i do manage to heel the boat past 18 degrees or so(possibly 20+, not sure yet) and actually submerge them.

    the vaka's not designed to separate and be an independent boat(which is a slick idea, actually) as mentioned earlier, but it can collapse down to a fairly narrow planform.

    i suppose where we're going with this is that you've put together a fair campout boat with some anyone-friendly characteristics and comfortable stability, and i'm putting together a bit of a adventurer's boat.

    and i'll admit this: cat, tri, they're both fun on the beach, when it's a set of tube hulls bolted or lashed to two pipes with a canvas or tarp stretched between them, and a nice gunter sail. when you're a kid, that's all you need. the tri tends to do better in races, when all skill is equal, but if you know how to handle it, a cat can really get up and move, and can be frankly more exciting when it heels over.

    and at least the way i always put them together, cats tended towards lighter, but i built my amas for flotation on the trimarans i made as a kid.

    as a note: if you're looking for a quick and dirty cat/tri for going to the beach in the summer, or making a little peewee for the kids, you can't go wrong with closed cell foam, shaped and then glassed. simple, tough, and really easy to make.

    same technique as surfboards, actually. similar to foam cored sandwich, but not as fancy. try it sometime. build up glass in areas that might be stressed more, and if you're really looking for simple, a tarp suffices for a deck.

    were i better with cad, i'd sketch it up and show you what i'm talking about for layout. it's actually a blast to make them. trimarans have the advantage of having attachment points for a headsail, or, if you're like me, a headsail and a staysail, if you put the mast back some. i always liked trimarans for the fact that you could really cram some sail onto them, and they'd usually forgive you once you got into the wind, and you take off like a rocket.

    ever see three teenagers on a 25' trimaran with three square rigged masts? i have. god that was a fun day, but holy crap we heeled over. ultimately it couldn't handle the pounding that three feet of surf gave it at 20+ knots. we managed to get a tow back from some guys in a fishing boat, but wow, those were some stories we got out of it. if i ever find the pictures, i'll share.
  9. rayaldridge
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    rayaldridge Senior Member

    I'd love to see drawings.

    I think your characterization of Slider as a camp-out boat for comfort-oriented cruisers is fair. The idea was to get the most luxury possible out of a 16 foot cat. I wanted to be able to trail the boat anywhere with a compact car, put it in the water, raise the mast, and be away in five minutes or so. I think that shorter time at the ramp is one of the big advantages a small cat has over a small tri.

    I'd also agree with you that in most circumstances, a tri will be faster than a cat of similar displacement.

  10. dsuursoo
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    dsuursoo Senior Member

    yeah, that lower wetted surface is the real key, i think. even when heeling over, the tri tends to have less hull in the water.

    and yeah, i'll give the slider that, setup would be a lot faster than immigrant son, since i'd have to get it in the water, then extend the outriggers, then lift the masts, then set the stays, then load it, THEN paddle out and set sails.

    and from your description of how slider's built, you can probably load a bit of gear in it before you ever hit the water.

    if i can ever get the drawings scanned and cleaned up, i'd be more than happy to post some. i'm trying to design this boat to be as simple and solid as possible, while still being put together mostly with hand tools.

    now, since i brought it up in my last post, anyone have any suggestions for design features in a beach cat/tri, given the construction techniques i've mentioned(shaped foam solid hulls, fiberglass coated) before?

    here, let's try design the optimal beach/overnight camping(not more than two, sorry ray, the slider's out of the running, as is immigrant son), go explore/impress the girls, have-fun-with-it beach multihull.

    actually, that might be better done in another post? votes on that anyone?
  11. peterwebb0
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    peterwebb0 New Member

    Astus 22.1

    Have you seen the new Astus 22.1 trimaran? I think that's one level up in beach camping in comfort.




  12. Manie B
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    Manie B Senior Member

    beautifull boat - great design

    far out frikken expensive

    you will NEVER see one anywhere in Africa

    28 000 pounds ?????
  13. Fanie
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    Fanie Fanie

    I agree with Manie.

    Good grief, that is a bit over.
  14. rayaldridge
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    rayaldridge Senior Member

    Slider video

    I just put up a new video-- the first part of my solo cruise in late

    There's some footage of porpoises near Fort McRee, which is across
    Pensacola Bay from Pensacola. This area is within a couple hours
    sailing time from Pensacola and Gulf Breeze, but is still pretty wild
    and undeveloped, especially if you have a shallow-draft boat without
    an internal combustion motor. The remnants of Fort McRee are really
    only accessible by boat or via a long drive by 4WD from Perdido Key.
    No roads, no condos, only a few boaters. I was all alone in the
    backwater behind the fort on Thursday night and Friday morning.

    I'm still learning how to use my new video cam, and I must warn you
    that watching my shaky camera work might result in convulsions. But
    there's a corresponding post on the blog, if you don't want to risk it..


  15. Zilver
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    Zilver Junior Member

    Tony Bigras has completed his microcat 16' MISS CINDY about which I posted earlier on in this thread.
    He's transported her to Mexico on the roof of an old car to go sailing there.
    His humorous and inspiring blog can be seen here :

    I think it's a beautiful, cool, clever and cozy boat. I like his way of just doing things out of the ordinary.

    Regards, Hans
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