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    Re: Ships as dancers
    From: Kev
    Date: 2010 Mar 16, 22:27 -0700


    ..." I've always been fascinated how in my kayak, a bit of yaw when surfing a wave very rapidly gets converted into a roll."

    Could this be the resonance phenomenon of 'parametric rolling' ?
    With the yawing a time varying change in the kayak's transverse stability could occur. Certain encounter periods of following or quarterly seas coupled with crafts natural half roll period can cause parametric rolling in large ships, fishing trawlers and yachts, so why not in kayaks?

    'Seaworthiness, the forgotten factor' by C.A.Marchay has a chapter on this type of rolling in yachts. The IMO(International Maritime Organisation)has a circular MSC 707 which covers wave and ship conditions that can lead to parametric rolling.

    Regards,

    Kevin
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