Weight concerns about a boat I'm considering purchasing

Discussion in 'Stability' started by Bruce Hess, Jul 24, 2008.

  1. Bruce Hess
    Joined: Jul 2008
    Posts: 31
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    Location: Alaska

    Bruce Hess Junior Member

    Can anyone give me some advice on a 32 downeast yacht I am considering making a offer on?

    It is a BHM 32 hull designed by Spencer Lincoln powered with a 260 HP 3208 cat. My concern is that this hull and power configuration normally has a 14 knot cruise and normally weighs about 14000#. This is based on conversations I've had with a current manufacturer of this design, Atlantic Boat Company.

    The boat I am considering was laid up extra thick and has some other characteristics that have increased the weight to 20,000# and has a cruise of 9 knots at 5 gph.

    Is there anyway to know whether this extra weight has caused detrimental effects or repowering the boat with a more modern lighter weight diesel could a achieve a moderate increase in speed without a considerable increase in fuel consumption? It seems, at present, that the weight may have negated some of the positives usually achieved by the semi-displacement aspects of its downeast design.

    How expensive would it be to have a NA run some calculations and are there any recommendations of someone with downeast hull experience that could do this for me?
     
  2. Tad
    Joined: Mar 2002
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    Location: Flattop Islands

    Tad Boat Designer

    View attachment Fuel use comparison.xls

    The attached table compares a range of Maine Lobster boat type hulls, various lengths and weights, showing fuel burn differences at expected speed.

    A 32' weighing 20,000 is seriously overweight, these hull forms are designed around speeds of 15-25 knots. The shape is all wrong for 9 knots. Different engine may help, probably a different gear and prop may be more to the point.

    This boat is not an efficient runner, therefore I would stay away.
     
  3. juiceclark

    juiceclark Previous Member

    A plastic surgeon friend of mine just spend a million bucks on a 40' Cabo sportfishing yacht. He hates it because it's too "corky." I've heard this from several people lately in these new, heavily cored to be light boats. When you get out in the slop the weight helps buffer the beating.

    I'll bet you can find ways to lighten the load a bit if you really like the boat. But Tad is right, there seems to be something else wrong...like prop size, bottom growth, a heavy and wet cored deck somewhere, engine problem, etc. etc. etc. A survey is the only way on a deal like that if you think it's worth it.
     
  4. Bruce Hess
    Joined: Jul 2008
    Posts: 31
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    Location: Alaska

    Bruce Hess Junior Member

    I'm suspecting that the prop is sized incorrectly. Could the wrong prop slow a boat like this 6 knots.
     
  5. juiceclark

    juiceclark Previous Member

    ....sure it could. And that's a lot of "extra glass!" Was something patched or a flaw over-compensated with strength? Who know...but you'd better have a survey check all that out before jumping-in.
    TC
     

  6. Bruce Hess
    Joined: Jul 2008
    Posts: 31
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Alaska

    Bruce Hess Junior Member

    Thanks for the advice on the survey. I do have a survey from 7-07. It doesn't report any patching or other damage. The original owner has indicated the boat was laid up extra thick because he wanted the boat extra stout. I'm also suspecting the weight has been overstated. I'm having present owner weigh the boat to verify. If the weight comes in in the 15,000 pound range I'm going to have Tad Roberts do a propulsion analysis to identify any problems with prop size and or reduction gear issues. If this detects that the speed could be corrected with adjustments to these items I'll pursue a survey and possible offer.
     
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