Sea Shadow is unlike conventional small-waterplane-area twin hull (SWATH) ships in that it is of "A" Frame configuration; that is, the struts are canted at an angle. A series of model tests showed a significant reduction of ship motions for the 45° selected strut angle.
The crew described her as fairly comfortable in heavy seas. A couple of times when they were out in sea state 5 (8-12 foot tall, 3-10 sec period) their Navy or Coast Guard escorts left the mission, but Sea Shadow was able to carry on.
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