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3988 Hull Distortion While On Blocks-gctid801403

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    3988 Hull Distortion While On Blocks-gctid801403

    Hauled our 1996 3988 yesterday for a bow thruster installation and had the shipyard look at the dripless shaft seals for possible replacement. The bellows make it look like the engines are low in the rear and need adjustment. I didn't notice this when it was inspected in the harbor. Is it possible for the hull to distort that much and things will be fine once it's back in the water? One reason I ask is some things in the boat don't seem to close or line up like they did when she was floating. Thank you.

    Jay, welcome aboard. Is this a new boat for you undergoing its first haulout. What other things don't seem to be lining up?

    To answer your question, short of something structural happening in the hull or stringers, I have not heard of significant twisting/bending that you are eluding too. From what I have witnessed, compared to other brands, Bayliner hulls were built like a tank. I presume there is adequate spaced support under the keel that is level and not contributing to a bowing effect. Are the stringer engine mount "L" brackets tight against the stringers? You were there when the hauled it out correct? If it was so far out of alignment, there would be significant vibration.

    While you have it on the hard, now might be a good time to have an accredited marine engineer take a look (including shaft alignment) to see that nothing is amiss.

    Good luck with it. Cheers
    John H
    Brisbane QLD Aust

    2000 - 4788/Cummins 370's


      " Is it possible for the hull to distort that much and things will be fine once it's back in the water? "

      Most every recreational boat in this size range will have some hull distortion even when it is properly hauled and blocked.

      That is why every set of directions concerning shaft alignment calls for a period of 2 days or so after re-launching prior to completing the shaft alignment.

      Those 2 days or more allow for the hull to come back into 'normal' shape prior to setting up the alignments especially after a long winter storage on land.

      With all that said I have seen a couple of times where boatyards have had various boats blocked insufficiently or at poor locations along the hull.
      Northport NY


        When "Mr. Darcy" was on blocks the transom door worked flawlessly. When it is in the water, the door tends to bind when closed. The door is not factory, but a somewhat crude modification done by someone hired by the PO. So yes there can be at least some distortion. Even a well built hull will distort if improperly, insufficiently blocked.

        Newport, Oregon
        South Beach Marina
        1986 3270 with twin 110 HP Hino diesels. Name of boat "Mr. Darcy"
        Past work history: Prototyping, tooling, and repair for Reinell,. General fiberglass boat repair starting in 1976.
        Also worked as heavy equipment mechanic, and machinery mechanic for over 30 years.


          As smitty477 stated, this is common with recreational boats. I used to keep my previous boat at a dry marina called, Dagmar's. Because of the uneven flex caused by dry storage, many of the larger boats there have keel supports, as well as multiple hull supports.
          1999 3788, Cummins 270 "Freedom"
          2013 Boston Whaler 130 SS
          Anacortes, WA
          Isla Verde, PR