Sea State, Vessel Depth, Freeboard

Discussion in 'Boat Design' started by Leopard, Dec 12, 2022.

  1. Leopard
    Joined: Nov 2021
    Posts: 47
    Likes: 4, Points: 8
    Location: Belgium

    Leopard Junior Member


    How to connect the sea state and vessel depth or freeboard for a particular route? Is there any minimum freeboard for a sea state? Is it okay only to consider the minimum wave height from the range of a particular sea state?
  2. Ad Hoc
    Joined: Oct 2008
    Posts: 7,843
    Likes: 1,730, Points: 113, Legacy Rep: 2488
    Location: Japan

    Ad Hoc Naval Architect

    The sea state is dictated by the route the vessel will take during its normal day to day voyage.
    That sea state will then dictate, what freeboard will be considered "acceptable". Do you want the vessel to slam and take on green water frequently, or not?
    So that in turn dictates the vessel's depth.

    That's it in a nut shell.
    Leopard likes this.
  3. jehardiman
    Joined: Aug 2004
    Posts: 3,838
    Likes: 1,211, Points: 113, Legacy Rep: 2040
    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    Just to add to Ad Hoc comments.

    For most vessels greater than 24m/150 gross tons
    The Load Line and its associated freeboard will be assigned IAW the International Load Line Convention.

    For all vessels it is prudent to do a forefoot slamming and motion analysis for the designed route. This is discussed in depth in Vol 3 of Hydrodynamics of Ship Design Part 4, Chapters 65 and 66
    Leopard likes this.
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.