Minimum Passagemaker/Cruiser

Discussion in 'Boat Design' started by mydauphin, Sep 29, 2010.

?

What is minimum that you can handle?

Poll closed Oct 29, 2010.
  1. I can only live in a proper yacht

    2 vote(s)
    6.1%
  2. Need: Size between 40 and 50 feet

    8 vote(s)
    24.2%
  3. Need: Size between 30 and 40 feet

    15 vote(s)
    45.5%
  4. Need: Size smaller than 30 feet ok

    8 vote(s)
    24.2%
  5. Need: Power

    22 vote(s)
    66.7%
  6. Need: Sail

    19 vote(s)
    57.6%
  7. Need: Single Engine

    24 vote(s)
    72.7%
  8. Need: Twin Engine

    5 vote(s)
    15.2%
  9. Need: Head and holding tank

    26 vote(s)
    78.8%
  10. Need: Air conditioner and Generator

    7 vote(s)
    21.2%
  11. Need: Watermaker

    15 vote(s)
    45.5%
  12. I don't care if interior looks like my garage

    8 vote(s)
    24.2%
  13. Need: DC Power Only

    15 vote(s)
    45.5%
  14. Need: Carpeting

    4 vote(s)
    12.1%
  15. Need: Wood floors

    9 vote(s)
    27.3%
  16. Need: Satellite TV

    3 vote(s)
    9.1%
  17. Need: Internet

    13 vote(s)
    39.4%
  18. Need: Hot Water Shower

    18 vote(s)
    54.5%
  19. Need: Manual Bilge pumps

    17 vote(s)
    51.5%
  20. Need: Propane Stove

    16 vote(s)
    48.5%
  21. Need: Freezer

    12 vote(s)
    36.4%
  22. Need: A boat that won't shame me at the marina.

    12 vote(s)
    36.4%
  23. Need: Windlass

    18 vote(s)
    54.5%
  24. Need: Dingy

    26 vote(s)
    78.8%
Multiple votes are allowed.
  1. michael pierzga
    Joined: Dec 2008
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    Location: spain

    michael pierzga Senior Member

    Ya...not a motorboat man myself. Think if you want to go motor it should be one of the motor cats. People tell me the motion is better. The other problem with motor yachts ...on any thing that anyone reading Boatdesigh.net can afford , is space. Machinery and tankage take up huge volume on a motorbaot.
     
  2. apex1

    apex1 Guest

    What would that be in your opinion? Or better what do you expect to be the maximum the bd.net readers can afford?

    Cats have a rather nasty motion in some sea conditions, especially motor cats. And they cannot cope with really severe conditions as monos. So cats are out of the race for true blue water cruising.

    Chuck,

    as much as I like Tad´s small designs, that 40ft boat is not really a liveaboard for a couple on ocean passages, do you think?
    Double bed in the bow, not useable at sea
    No sea bunk
    Engine not easyly accessible, (no engine room)
    Galley not seaworthy, too much space behind the cook
    to name just a few points very obvious from the plan.

    I would not take the longest distance between bunker stations as a measurement, though that is mandatory to be covered of course. More important is imho the comfort on passages. Fatigue kills, and a 40ft boat in not too bad weather is already a pain for days and nights on end. In severe weather a uncomfortable ride can kill the crew by fatigue. That is, and was always, besides speed, my main argument for a longer vessel. And I will never, never agree, that a 40 ft boat is safe on passages in these regards. What does scare the people to go longer? I cannot understand that, it is just insane.
    I am just back from Cyprus on the 57ft trawler, shown here for sale. That was only 36hrs (though singlehanded), on a rugged boat and not really bad weather, but I feel it in my bones. Smaller? No, really not.
    Of course when all the mouthopeners, not really planning to cruise, count their marina cost, it is easy to understand. But all these threads are talking blue water cruising over long periods, probably after retirement. Not dock sitting. But the dream and the reality....I know.

    Sure when surviving a trip is called sufficient, the shorter boats can possibly be called a choice. But when cruising has anything to do with enjoying life at sea over long trips and long time, they are not and will never be, that is just physics, nothing else.

    Regards
    Richard
     
  3. Tad
    Joined: Mar 2002
    Posts: 2,303
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    Location: Flattop Islands

    Tad Boat Designer

    Thanks to all for kind comments on my efforts.......In explanation of the PL39 layout.....it was done for a client who said, "can I have this and this and this, etc." The boat is intended to make long coastal passages, but ocean crossing in such a small (relatively) boat is a once in a lifetime exercise, not an everyday occurrence. Thus it is, as are ocean crossings in small sailboats....somewhat of an endurance effort.......As always the ideal for ocean passages is not very liveable in port where she spends 99% of her life.....

    Someone mentioned having a lathe aboard, I think that's a key to the "poor man's ocean cruiser". He will not be a wealthy retiree, but instead a average working joe....thus he must continue to earn a living while traveling. Lot's of folks do this right now, mechanic's, sail maker's, writer's, photographer's, etc. But to earn a living you need to have some space and some tools....so a bigger boat may be required.

    This brings me to the preliminary model below......60' by 10', with about 4'6" draft. Lapstrake plywood construction, all 3/4" hull planking with heavy glass sheathing below waterline. A simple deck curved in only one direction and built of two layers of 3/8" ply on longitudinal stringers. Backbone of laminated Fir. Single engine, the smallest John Deere or a 6 cylinder Isuzu......A fair bit of keel (outside ballast) and two masts to fly some sails....not a motorsailer but a sail assisted powerboat.

    A small cockpit right aft with drop-down transom ladder into the water. Then a 15' long aft cabin which will be living space, with watertight bulkheads fore and aft and opening to the aft cockpit as well as the center bridge deck. There's room for a galley, dining area, sea berths, even seperate sleeping cabins as required. Amidships is a well sheltered 12' long bridgedeck with engine and tanks under. And forward we have 20'+ of work and storage space......the head, laundry, office, workshop, and foc'sl storage is all up there......

    Passagemakingdory.jpg
     
  4. michael pierzga
    Joined: Dec 2008
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    Location: spain

    michael pierzga Senior Member

    Sixty by ten should move thru the water nicely. Cant see the deck layout geometry. One curse of smaller boats, that are meant to do big customer things , is on deck human ergonomics. Cabins take up so much space that side decks or any space required to perform tasks becomes minimized.. On deck is the life on a coastal boat
     
  5. Man Overboard
    Joined: Oct 2006
    Posts: 246
    Likes: 13, Points: 0, Legacy Rep: 129
    Location: Wisconsin

    Man Overboard Tom Fugate

    10' (3.05 m) seems awfully thin for a passage maker. What would the waterline beam be? A 5:1 Length-to-beam ratio gives 12 ft (3.66 m). Is comfort at sea going to be significantly less if you go 2 or 3 feet wider? Will fuel consumption on a displacement boat change any appreciable amount when going from a 6:1 to 5:1 length-to-beam ratio? Just asking; it seams that for accommodations sake 12 or 13 feet would be far better.
     
  6. michael pierzga
    Joined: Dec 2008
    Posts: 4,862
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    Location: spain

    michael pierzga Senior Member

    Long thin boats are beautiful at sea and very efficient.
     
  7. gunship
    Joined: Jun 2009
    Posts: 144
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    Location: Sweden

    gunship Senior Member

    and somewhat more rolll prone, and "heavier" (less boyancy) in the ends?
     
  8. Tad
    Joined: Mar 2002
    Posts: 2,303
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    Location: Flattop Islands

    Tad Boat Designer

    See this.....http://www.tadroberts.ca/about/pdf/brief-history-of-lightweight-motoryachts.pdf

    Of course a wider boat will be roomier.....it will also be heavier and take more time and money to build and move.....a increase in beam from 10' to 12' is a 20% increase in displacement. This adds 4500 more pounds of boat to build (perhaps 2000 additional hours or one man/year), and 20% to build cost and operating cost (at least to fuel, insurance, and maintenance, not moorage).

    This brings us back to the primary question......What's "Minimum"?
     
  9. Tad
    Joined: Mar 2002
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    Location: Flattop Islands

    Tad Boat Designer

    ....Why?
     
  10. michael pierzga
    Joined: Dec 2008
    Posts: 4,862
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    Location: spain

    michael pierzga Senior Member

    Id suggest you study Nigel Irens design approach...as well as the navies of the world. Long and thin makes for very seaworthy boats. Beam is good for floating bulk...aircon, generators and many kitchen sinks.

    http://www.nigelirens.com/ldl/
     

    Attached Files:

  11. gunship
    Joined: Jun 2009
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    Location: Sweden

    gunship Senior Member

    I dont know. Hence the question-mark ;)

    I know roll is not synonymous to beam, but I figure very thin is still more susceptible to rolling (or needs more ballast or other dampening details).

    And I figured that since the ends are very thin, they have less boyancy and would dig in a wave more often.

    I'm still just guessing, gee! I'm an uneducated (in the subject) amateur fer christ sake!
     
  12. apex1

    apex1 Guest

    Rolling home
    rolling home,
    rolling home across the sea.........[​IMG]




    ..but we are coming closer, thanks Tad!;)
     
  13. Man Overboard
    Joined: Oct 2006
    Posts: 246
    Likes: 13, Points: 0, Legacy Rep: 129
    Location: Wisconsin

    Man Overboard Tom Fugate

    That would not be 20% increase in displacement, rather about 17% increase in volume. A 17% increase in interior volume does not necessarily mean a 17% increase in displacement, unless you increase the weight of everything 17%... not likely. In addition it would not add 20% extra to the build cost, unless of course everything in the boat cost 20% more, again not likely, we're talking just two extra feet, that's 2 feet on the bottom of the hull, and 2 feet on deck; as well as any bulkheads, and maybe slightly heavier scantling. There would be an increase in labor for the Hull structure not the entire boat.
     
  14. gunship
    Joined: Jun 2009
    Posts: 144
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    Location: Sweden

    gunship Senior Member

    Apex, that seems like a pedagogic learning sheet, by the looks of the notation.
     

  15. Pierre R
    Joined: May 2007
    Posts: 461
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    Location: ohio, USA

    Pierre R Senior Member

    If you don't find the weight to increase it by the 17%-20% you are gonna get tossed even worse. Bluewater boats need a certain loading per square foot of waterplane or you are gonna get hammered. Your screen name might become most appropriate.

    Apex is right, fatigue and sea sickness can easily kill you.
     
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