Deck/Hull Height. and Scuppers.

Discussion in 'Boat Design' started by member74761, Sep 17, 2021.

  1. member74761
    Joined: Aug 2021
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    Location: USA

    member74761 Junior Member

    This question is a little odd. But I have good reason.
    I will be adding scuppers in my build.
    There was a single drop pit or small pan to describe it.. 8"x8"x2" recessed in deck that drained through transom garboard type drain. this was floor or on deck to be clear.
    From the outside water stain/line this was well below water and seems it would have flooded the deck.
    In placing the scuppers, and to add to that I need to do a float test.
    I'm sure I need to raise the floor or deck height, for several reasons.
    Not only to get above water line, but also give room for below deck fuel tanks, that weren't there. And that all plays back to my float test and how she will sit in my arranging of things.
    So back to the question after all the details..
    Is there a minimum sidewall or hull height from the floor/deck to the top of the hull.
    I think right now it's about 18" and there is a raised area past the center console at the bow(kinda typical)
    My "Idea" is raise the floor 2"-4" But much more, we start approaching 12" side hull.
    And I don't want it to be goofy/unsafe or uncomfortable for others, or especially IF I happen to sell it later.
    Is there a magic number out there or "code" or is it ok to just be what it is. when it's all said and done.
    This is still in the planning stages. so its nothing I have nailed down yet.
    Still several parts to this pending, but getting the base line parameters and having a starting point would help.

    I appreciate the thoughts in advance
     
  2. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    I am finding it difficult to try to visualise what you are proposing - can you post any drawings or sketches that you have for your boat please?
     
  3. member74761
    Joined: Aug 2021
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    member74761 Junior Member

    I don't have any pic's or drawings.
    The simplified question is.
    Is there a minimum desired or safe height from the floor or deck to the top of the side hull or gunnel.
     
  4. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    a paddleboard is "self-draining" and has zero sidewall height. In terms of what kind of internal freeboard height is desirable, when people are standing up using it as a brace, about 27" I would say is the minimum.
     
  5. member74761
    Joined: Aug 2021
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    member74761 Junior Member

    Ok thanks.
    originally from factory this one is about 18" as I had said.
    If I raised the floor in my build back It could end up at 15"-16"
    Some bass boats are almost a floating barge with 0 sides, like you described the paddleboard.
    I have this vessel completely dismantled, cap removed, and complete build back ahead.
    So I could make it whatever I choose.
    I just wanted some insight from the site.

    Thanks again.
     
  6. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    Low internal freeboard you can't brace your knees against is the issue, bracing with the shins seems not as effective ! Find a piece of furniture in the house and brace your leg up against it, you may find something you think is high enough, just measure it.
     
  7. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    You can always add rails to a boat with low freeboard or low bulwarks.

    AF604BCF-28B4-4E92-8DEC-6D290500A117.jpeg
     
  8. member74761
    Joined: Aug 2021
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    Location: USA

    member74761 Junior Member

    I appreciate the feedback.

    Thanks again as always.
     
    fallguy likes this.
  9. Barry
    Joined: Mar 2002
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    Barry Senior Member

    A simple question but quite a bit of requirements in the ABYC manual.

    I am not aware of the type of boat that you are building so cannot narrow down the standards

    They are contained in the ABYC standards under H41 "*****Rails***" 41.6 d. Coaming, gunwale, bulwark or enclosure of at least 24 inches above the deck (exception open boats---a. that has a permanent enclosed shelter for persons or
    a permanent structural weather deck at least as high as the sheer and at least half the length of the boat---it does not appear that your boat is included)

    But the topic becomes a bit more complicated as there is another section H-4 Cockpit Drainage Systems that discusses the cockpit and scupper requirements, sizes, minimum height above the loaded water line, water tightness of the cockpit
    deck, strength of the cockpit deck and the height of the cockpit deck above the scuppers, under at least two defined types of cockpit drainage systems 1) Quick Draining Cockpits, 2) Self Bailing Cockpits

    Further conformity requirements are contained in H-27 Seacocks, Thru-hull fittings and Drain Plugs

    The ABYC manual is expensive but if you are spending thousands on a new build, it will save you money and answer questions regarding Equipment, Electrical, Hull and Machinery.
     
    Last edited: Sep 18, 2021
    bajansailor likes this.
  10. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    @Barry

    sure wish abyc had a one time use book that was affordable
     

  11. Barry
    Joined: Mar 2002
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    Barry Senior Member

    They run about $500 US if you are not a member and $80 if you are. The information contained within about a 2 inch thick book plus another inch thick of supplements covers so much information with the idea of developing standards
    to make boats safe. Hard to put a price on that. Additionally the cost of doing something incorrect and then having to correct the deficiency to make the boat conform to get insurance under the approval of a marine surveyor can be saved
    if it is built correctly the first time. Another benefit is the time saved trying to research various sources regarding equipment and material if it is your first build.

    I have not checked recently but Canada runs just about the same information which is on the internet at no cost. I cannot remember the exact reference but should be easy to find. I also am not sure if it is in the same detail as the
    ABYC book. Another source may a library, and if there was an online library, that would be so much better.

    Perhaps a call to a few NA's offices to see if they have older copies that they do not use as they purchase the newest edition may also be a source.

    I would wonder if ABYC could make the book available online in a format that cannot be downloaded to print. Ie pay a stipend say $100 and you have access for a year, log on, submit a pin, just to read over the pertinent info
     
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