Bunk alignment in a small boat

Discussion in 'Boat Design' started by jbo_c, Mar 31, 2020.

  1. jbo_c
    Joined: Jul 2017
    Posts: 43
    Likes: 6, Points: 8
    Location: Gainesville, GA

    jbo_c Junior Member

    Is there a reason to orient berths parallel or perpendicular to the length of a small boat? Or is it more a function of having sufficient beam to orient them perpendicular for that to be an option

    Would there be more perceived rock if oriented perpendicular to the length? Seems like there might be. But, on the other hand, a place quiet enough to put down for the night likely wouldn’t have enough motion to matter much(inland, at least).

    What do you think?

  2. wet feet
    Joined: Nov 2004
    Posts: 652
    Likes: 97, Points: 28, Legacy Rep: 124
    Location: East Anglia,England

    wet feet Senior Member

    Define small boat?I have put a double berth parallel to the topsides in a good sized motorboat forecabin.Slightly more bizarrely I had the job of fitting out a 27 footer back in the eighties with the owner's sketch to define the layout.You might not think that too unusual,but he had specified a double berth going athwartships in the middle of the boat and you had to use the table to fill the central walk way.Not only did it cut access through the boat but the support post for the deck stepped mast went right through the middle.They tell me the customer is always right...........
  3. jbo_c
    Joined: Jul 2017
    Posts: 43
    Likes: 6, Points: 8
    Location: Gainesville, GA

    jbo_c Junior Member


    I’d like to use the 7’ width for the berth so I take up minimal boat length. But if that layout magnifies perception of movement, it’s probably not the way to go.

  4. gonzo
    Joined: Aug 2002
    Posts: 15,129
    Likes: 901, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    On sailboats, if the berth is perpendicular to the centerline, it would be impossible to sleep in it underway. You would slide to the lower side.
  5. jbo_c
    Joined: Jul 2017
    Posts: 43
    Likes: 6, Points: 8
    Location: Gainesville, GA

    jbo_c Junior Member

    Ha. Good point, Gonzo. This would be a flat bottom motor boat(not totally unlike a canal boat) and any real sleeping would only be done at anchor.

  6. fishwics
    Joined: Mar 2004
    Posts: 33
    Likes: 1, Points: 8, Legacy Rep: 10
    Location: UK

    fishwics Quiet member

    The bunks on traditional British narrow canal boats frequently went transversely. (6ft 10in beam)
  7. BlueBell
    Joined: May 2017
    Posts: 1,563
    Likes: 393, Points: 83
    Location: Victoria BC Canada

    BlueBell "Whatever..."

    If there's gonna be rolling or pitching, then you want to be close to the center of motion.
    When it's bad, I sleep on the floor.

    EDIT: I probably should have said "center of rotation", not "motion".
    Last edited: Apr 1, 2020
  8. Ike
    Joined: Apr 2006
    Posts: 2,472
    Likes: 335, Points: 83, Legacy Rep: 1669
    Location: Washington

    Ike Senior Member

    Have you ever tried tried sleeping on a rocking boat when perpendicular to the centerline? Doesn't work out too well. Parallel reduces the chances of sliding and the bunks can be hinged up out of the way when not in use, and in rough seas tilted up a few inches so you don't get tossed out. If the boat is going to be used on flat calm water all the time like on small lakes or canals then it doesn't matter, whatever arrangement works. But if you are using it on large lakes, bays, or open ocean the it matters a lot.
  9. jbo_c
    Joined: Jul 2017
    Posts: 43
    Likes: 6, Points: 8
    Location: Gainesville, GA

    jbo_c Junior Member

    Thanks, all.

    Ike, that’s pretty much what I was thinking.

  10. DCockey
    Joined: Oct 2009
    Posts: 4,895
    Likes: 434, Points: 83, Legacy Rep: 1485
    Location: Midcoast Maine

    DCockey Senior Member

    Even on sheltered waters a boat will rock from the wakes of other boats.
  11. clmanges
    Joined: Jul 2008
    Posts: 423
    Likes: 60, Points: 28, Legacy Rep: 32
    Location: Ohio

    clmanges Senior Member

    Might hammocks be applicable? Probably not in that size of boat ... if it's only for one person you could maybe string a cargo net across the width of the boat and the person could sleep lengthwise. Just thinking out loud.
  12. jbo_c
    Joined: Jul 2017
    Posts: 43
    Likes: 6, Points: 8
    Location: Gainesville, GA

    jbo_c Junior Member

    A hammock or pipe bunk in many cases would be a good idea, but this specifically will be a double berth.

    Thanks for the response.


  13. JSL
    Joined: Nov 2012
    Posts: 805
    Likes: 58, Points: 28, Legacy Rep: 41
    Location: Delta BC

    JSL Senior Member

    I have slept on bunks of both directions: fore/aft is good...athwartships is awful, even if with slight rocking. But, some people might be less affected.
    On a sailboat, there is no option - athwartships is out. If you were sleeping during a knockdown you could break your neck.. or your ankle.
    As to 'perpendicular'...… I have trouble sleeping while standing up.
    Last edited: Apr 4, 2020
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.