Thinking About Taking On 50 ft Houseboat Build

Discussion in 'Boat Design' started by cpenrose, Jul 23, 2013.

  1. cpenrose
    Joined: Jul 2013
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    cpenrose New Member

    Hello I'm new to the forum. I'm 14 and I love building things, especially boats. I fix everything and enjoy being outdoors,especially on the water.( I'm a saltwater person by the way). Anyway, my dad and I are thinking of building a 50 foot houseboat. I've built 6 very small boats myself. He's not very good mechanically. I was thinking of doing it with 5 foot wide pontoons(2), and 15 feet wide overall. How deep should they be to support a 2 floor boat when the top would just be a deck? We don't really plan on riding around, just moving. Or should I do a regular v bottom or a tri hull? I was also wondering about jet ski power. What if there was a cut out in the back of the pontoons where a jetski could be pulled into where it still sits in the water that we could power the boat with and then pull them out. Another idea is to recycle bottles on the pontoons to add flotation. This would save a lot of money on foam as we'd only need to fill in the gaps. Whadda you guys think?
     
  2. PAR
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    PAR Yacht Designer/Builder

    Welcome to the forum.

    Building a boat is wholly different, then designing and building a boat, especially a 50'er.

    Considering your age and experience level, you're not yet able to design a 50' boat. With your building experience, you might have some luck with a 15' boat, but 50' is way over your head right now.

    Do yourself a big favor and buy Dave Geer's book: "The Nature of Boats". This will inform you of the basics and you get a feel for the skills you'll need to design a 50' yacht.

    Pontoons are the last route to go on a boat like you've described, (I have a 50' riverboat in my gallery). The only reasons pontoons are used are; they can be made easily, cheaply and you can crank them out by the dozen each day. They're not used because they're efficient, or especially well suited to fast moving powerboats. In fact they're about the worst approach you can take hydrodynamiclly speaking.

    Using recycled bottles is an effective method to get cut rate floatation, but on a 50' boat, this is simply not reasonable. Once a boat gets over a ton and a half maybe two tons, the volume to float it with reserve buoyancy (floatation) becomes way too big to have any interior left, so we resort to compartmentalization instead. This lets you have your cake and eat it too, as these spaces can still be used for something, but sealed off when necessary, to act as floatation.
     
  3. cpenrose
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    cpenrose New Member

    By the way I meant Catamaran style pontoons, not the aluminum ones. We're likely going to do the 45' Bon voyage design from glen-l.
     
  4. PAR
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    PAR Yacht Designer/Builder

    The Bon Voyage is a warped bottom mono hull, not a cat. The performance figures listed seem, well, overly optimistic, to say the least.
     
  5. Petros
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    Petros Senior Member

    welcome to the forum.

    a 50 foot house boat is a big and costly project to take on. You might consider going to a few boat yard auctions and see what incomplete projects you can pick up for far less than the material cost alone. Going with Glen-L plans is a good start as well, if you are determined to build from scratch. the designs have been around a long time and are well respected.

    You also might also consider something much smaller as a first project. Use professional boat plans and after you enjoy it for a few years you can likely sell it for a reasonable price and than build the larger one you really want. The cost of building a boat goes up with a exponentially with the length, as does the maintenance and up keep. for example, building a 35 ft houseboat would likely cost less than half of building a 50 ft one, and building a 25 ft boat can be done for about one fourth the cost of a 50 ft boat.

    Good luck.
     
  6. PAR
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    PAR Yacht Designer/Builder

    Call around for slip fees, just to get a wakeup call on a portion of the ownership of a 50' vessel. We're not trying to pick on you, it's just a common misconception, thinking you'll build the big dream boat, first time out of the gate. I have a 37' and 65' yacht, both in slips, so I have a fair idea about the ownership costs associated with this class of vessel. You could build my Chiusa (26') or Egress (28') designs for a fraction of a Bon Voyage.
     
  7. philSweet
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    philSweet Senior Member

    The hard part to understand is that the ownership cost - the cost per year to maintain a vessel - starts pretty much when you begin the build. So you have to deal with maybe $10,000 a year in costs in addition to whatever the boat costs to build. So you need to get organized to the max before you start building stuff. And then "git her done".

    Some things that you should be do before any stuff gets bought-

    A statement of requirements (SOR)- what speed, what weather, what season, what body of water, and what purpose will the boat be used.

    A propulsion system design. What you describe is called a yawlboat system, where a utility tender is also used to shift the motherboat around. A non-powered live-aboard is usually termed a floating house. A houseboat is self propelled. The difference is sometimes important as far as legal matters are concerned.

    A bill of materials for the hull and superstructure. This means you have to have a sketch and it has to be good enough to actually order materials off of. Do you know what every piece weighs? You need to know that.

    As PAR has said, It would be a good idea to build a smaller boat, probably from a kit, in order to gain the experience needed to build a 50'er. You will probably be 25 by the time the 50'er gets launched if you don't. I spent nine years building a 16', #350 boat. Next one took three years. 3rd boat took 4 days. Practice makes perfect.

    Also, you need to appreciate the efficiency of of a factory boat. If you were to buy all the parts to build a Ford Mustang from NAPA, it would cost you about $150,000. Then you have to assemble all the parts. Same with home-built boats. A factory can pay less for labor + materials than you will for just the materials.

    So to build something like this - http://www.boattrader.com/listing/1998-Gibson-Cabin-Yacht-353017 - you would probably spent $200,000 on materials alone, and it would take many years for two people to build in their backyard in their spare time.

    Of course it doesn't have to be like that. There is a camp trailer mounted to a big skiff hull in Florida that has survived countless hurricanes; but I can't figure out why it hasn't sunk.
     
  8. cpenrose
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    cpenrose New Member

    OK so first off I have built boats before, one 9'er that turned out great and took me two weeks, and a 14'er that took about 2-1/2 months then I got it epoxied in the seams, then went on vacation. The tarp blew off and It got soaked. I had to let it dry, and we also had a party so I had to move it back in my yard. I went back to it a little while later and it was rotted. Before these I built an 8ft jon boat which worked pretty well but since I was about 11, I used silicone... lol, so it leaked a bit. Tried to build three while I was younger, and they didn't turn out well. The two recent ones were off of plans. Second off, we own a 1988 35' Luhrs Alura. It's an express with twin chrysler 360s. I do all the maintenance and there's a lot of it. We know all about the whole boat price thing. 25-30 grand into it since we bought it last July.
     
  9. keysdisease
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    keysdisease Senior Member

  10. PAR
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    PAR Yacht Designer/Builder

    Jets need to "run" to anything close to efficient. Marrying a jet to a monolith is just asking to cook it quickly. The pontoon does move in that thread, but uses a lot more fuel than an outboard.
     
  11. parkland
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    parkland Senior Member

    You should try to build something that can be towed behind a normal pickup truck, then your costs go way down.
     
  12. keysdisease
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    keysdisease Senior Member

    I agree, the pontoon in the video is moving pretty good, probably too much IMHO for whats good for the engine, but, if you're only going a mile or so to the local sandbar to drop the hook on the pontoon and play on the waverunner, it really doesn't matter if you just putt putt there does it?


    :)
     
  13. hambamble
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    hambamble Junior Member

    Working full time I don't have enough money to buy, build or own a 50 footer. I think the other comments were really useful. Build something you can tow and the costs go wayyyyyy down. Alot of people don't quite understand that if you double the size, the volume actually goes up by a factor of 8. So rough calculation makes it about 45 times bigger than the 14 footer you built, and i would say in reality, it would be closer to 100 times the hours. I am not trying to discourage you from building a boat, but i think something smaller would be better. Also, if you want to ever make any money back on it, you need to use good quality materials which last, like marine grade ply, stainless steel or bronze fastenings, good quality epoxy, etc. If you do it on the cheap, it will be junk and have no resale value. If you want to keep it for a long time it won't last

    Get an excel spreadsheet, and cost it all up. You will be really surprised how much it costs. You don't think about things like hoses, wiring, valves, screws, bolts, nuts, nails... galley sinks. In a 50 foot boat the fitout alone would cost tens of thousands.

    Also, I think you'll have more fun with a boat you can actually finish before your retired, rather than one that will take you the next 50 years to build. Build a 20 or 25 footer and you will have loads of fun, and finish it with a few years of hard work.

    I used to build stuff all the time at that age, and most people would criticize me when i started the build... not when i finished. If you want to do something, do it, but I really think that a 50 footer is too ambitious.
     
  14. cpenrose
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    cpenrose New Member

    Yeah after two forums of the same thing we decided to go smaller. We are possibly going to build the boat we'll use for fishing in Florida first. Then go from there. 31' Carolina Angler design from Glen-L. Not positive yet.
     

  15. dskira

    dskira Previous Member

    The Carolina Angler is not an easy boat to built eather

    [​IMG]
     
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