A catamaran for living aboard?

Discussion in 'Boat Design' started by Filmdaddy, Jun 26, 2008.

  1. Filmdaddy

    Filmdaddy Previous Member

    For the last couple years, I've been thinking about boats and convalescing. Now that I am able to start considering building again, I thought that I would ask some questions of this august body regarding cats that are not meant to be faster than anything else on the lake, but, instead, are intended to be very comfortable liveaboards. Why a cat? Stability, room, shallowest of drafts (in comparison to mono of the same cubic, anyway), ease of construction - glass over plywood. Given that I want storage, reduced pitching, strength over speed, what should I be considering?
     
  2. TeddyDiver
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    TeddyDiver Gollywobbler

    You didn't say were it meant to have sails or iron genoa? Or just for living?
     
  3. Filmdaddy

    Filmdaddy Previous Member

    TeddyDiver - sorry. Sails, probably junk rig. Idling from anchorage to anchorage without a timetable. Two people, lots of her clothes, room to stretch out and take pictures, fish, etc.
     
  4. TeddyDiver
    Joined: Dec 2007
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    TeddyDiver Gollywobbler

    Most of your criterias could easily fit to a mono hull aswell. Nothing against cats but if you don't need the best advantage of a catamaran so why to choose it.
    How much "freight", displacement, length etc...:confused:
     
  5. Filmdaddy

    Filmdaddy Previous Member

    Just investigating possibilities. I've been, for years, thinking about a sharpie. Even started putting together material a couple years ago, but medical problems intruded. Now that I'm back prepping and thinking, I want to find out about a displacement catamaran. I mean, the criteria would suit a tri better than a mono or a cat, in reality...
    Length would be about 30-35 feet, displacement would be definitely heavy for the length. Freight would be Darling's wardrobe, cameras, photo gear, computers - she travels in style - and my pants. (The added weight would stabilize quite well, I have read.)
     
  6. kengrome
    Joined: Jul 2006
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    kengrome Senior Member

    Will it be used on one of the Great Lakes, or on waters much smaller? Cruising to other locations or staying on the same lake all the time?

    It seems you want the boat for space, not speed, is this correct? Do you want lower draft than a typical 30-35 foot cat? Do you want easy beachability?

    Do you want a custom design or a set of off-the-shelf plans?

    Do you really need the sails, or would simple motoring be an acceptable alternative? You can save a lot of money by avoiding the sails and all their related components. Then again, you never said anything about saving money ...
     
  7. Bullshipper
    Joined: May 2008
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    Bullshipper Bullshipper

    I am a big catamaran fan, but the inner structure require to span the tunnel makes them a lot more difficult to build than a mono hull in my opinion, and the need to go to twin engines is another cost factor.

    Plus you need more beam to make them stable, so on land transportation problems of a 12-16 ' beam should also be considered.
     
  8. Filmdaddy

    Filmdaddy Previous Member

    kengrome... Coastal Great Lakes, Georgian Bay, Trent/Severn Waterway, St. Lawrence, staying up to a couple weeks at a time, depending. Absolute minimum exposure to big weather off the hook, out of a secure harbor. Boat is not for speed at all. Room and storage are much more important. Shallow draft is a good thing. Easy beachability is good as well. We're two retirees who want to boat around with most of the comforts we've become used to in our small but comfortable apartment, without the heeling of a sailing monohull, and the hobby-horsing of a light catamaran. We've got some medical concerns, so a custom design would be easiest. Sails are important, very strongly leaning toward a junk rig. Saving money is a very nice concept.
    Bottom line, we're gathering information and opinions, tips and reasons.

    Bullshipper... I'm not going to attempt to design anything. But I really want to know the ins and outs, and I figure this forum is the best place to get it. Twin engines aren't a problem. I've got that settled, whatever design we go with. And road transport isn't going to be an issue. Boat will be hauled or sailed south in the winter. Worst case, I lie up in New Brunswick or Prince Edward Island, and do a little exploring and writing. (The boat, whatever we go with, is going to be insulated and well-heated.)
     
  9. kengrome
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    kengrome Senior Member

    What health concerns are you referring to? Mobility issues or something else?

    If you really don't need or want the deeper draft of typical high-speed sailing catamaran hulls, I might suggest wider hulls for shallower depth and easier beaching. Or maybe you'd like to consider something like an enlarged Bolger Bantam. Here's a couple links to some duckworks articles with images to follow:

    http://www.duckworksmagazine.com/07/projects/bantam/index.htm
    http://www.duckworksmagazine.com/08/outings/florida/index.htm

    [​IMG]


    [​IMG]


    [​IMG]


    Obviously the Bantam is a much smaller boat than you're looking for. I'm posting the pictures to give you an idea of the concept, that's all. A larger boat build in a similar style might be a really comfortable live-aboard. The trimaran concept seems to work well here.
     

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  10. FAST FRED
    Joined: Oct 2002
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    FAST FRED Senior Member

    In my experience with multihulls they may have a FEW downfalls for your INTENDED LIFESTYLE.

    Load carrying in terms of weight is poor compared to a monohull.

    The surface area is quite high , so if either heat or air cond is needed the energy requirements are very high , even if insulated.

    Most travel lifts are of limited beam , so once the boat gets "too" wide it is difficult to find a travelift , and so few places have marine railways , THEY will do any required work , not DIY.

    Finally, we finished the LOOP last year ,and however careful your are there will be some contact with concrete lock walls.
    Multi hulls by their requirement for aircraft style light weight may suffer more than a "brick" .

    With the thousands of cheap monohulls that could be great cruisers , why not just buy a $10K cruiser and get on with it?

    If boat building is your hobby , have fun, but if cruising is the adventure , why build a boat when your requirements do not require a custom vessel.

    FF
     
  11. kengrome
    Joined: Jul 2006
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    kengrome Senior Member

    Multihulls have never been "required" to be built light weight.
     
  12. Filmdaddy

    Filmdaddy Previous Member

    OK... kengrome: Mobility issues. And I am really interested in the wider hulls concept. We had discussed this, especially with a hard chine and flat bottom. I had not heard of the Bantam, but the pictures are interesting. If it could scale up, it might work.
    FAST FRED: We're willing to build heavier to get more storage space at the expense of speed. If we decide to go cat, building heavier would make locking through easier, as well as giving us stability. The heating and cooling issues are important, but since we're just starting to explore the issue of how many hulls, it's just one of the potential problems that we'll have to deal with down the road. Or canal.
     
  13. kengrome
    Joined: Jul 2006
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    kengrome Senior Member

    Filmdaddy,

    The good thing about Bantam in terms of mobility is that the living space is all on the same level -- above the hulls -- which makes life a lot easier. A boat like an enlarged Bantam would actually be ideal for a wheelchair-bound person and his/her companion. Keep in mind that this is exclusively a power cruiser and not a sailboat.

    I would not suggest a direct scale-up of Bantam, but if you like the 'concept' a similar but enlarged custom boat would be relatively easy to design. I've sent you a 'private message' via this forum with some information you may find interesting, so please check your private messages when you have a chance.

    Getitng back to the boat's design, I tend to design for the actual use of a boat first, then worry about aesthetics later. The fact that you've already said these things:

    ... makes me think a boat similar to an enlarged Bantam might be the best type suited to your particular cruising style. On the other hand, you also said this:

    ... and Bantan is not a sailboat, it is exclusively a power boat.

    A similar but enlarged version could be designed as a sailboat of course, but do you really want to deal with both sails and engine power? On canals and narrow waterways, and when there's not enough wind (or too much wind) you'll be using the engine all the time anyways, so I wonder if the extra expense to design and build in sail power is really worth the effort?

    It might be worth the added expense if you plan to do most of your cruising in big bodies of water where the mast won't get stuck in trees for example, or where you have enough space to tack back and forth when trying to get upwind. But unless I'm mistaken, the description of your cruising grounds would make sailing possible only for a very small portion of the time you're actually on the water, and this is why I wonder if you would really need the sails at all?
     
  14. harlemriverman
    Joined: Oct 2005
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    harlemriverman Senior Member

    cat's a logical choice for a live-aboard. advantages are many, which you seem to sense.

    trade-offs are in its performance characteristics, mooring options, and privacy but this is all hair-splitting if its more of a house-boat that you take out for leisurely jaunts in open waters you know well.

    a mono hull will prove of greater utility over-all, and certainly be less frustrating, if the agenda is to live aboard and travel liberally. you'll burn less fuel, enjoy all the creature comforts you need, and have more flexibility on where / how you port of call.
     

  15. Filmdaddy

    Filmdaddy Previous Member

    harlemriverman: yeah, cats have a lot going for them. One thing not immediately apparent is that theDarling says she doesn't like the idea of spending much time a-heel. And the Darling always gets what she wants. Performance isn't an issue, not speed performance, anyway. Stowage, insulation, comfort, those are more important. We'll be spending time cruising, but never in a hurry and never to anyplace that others would find exciting. Gunkholing is a must, photographs always, lying to for weeks at a time... that sort of thing.
     
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