Like anything else involving waves in large bodies, this depends on a lot of things. In large, open water in calm water, waves energy doesn't dissipate. In winds, wave energy does dissipate if the direction of the wave is against the direction of the wind. If wave energy is in the same direction as the wind, large wakes promote the phenomena called "the three sisters." Anyone who wants to study this phenomena should cruise the Chesapeake Bay or the Delaware Bay, where there is both large ship traffic and long fetch winds. On more than one occasion in 3 - 4 foot seas, I have underestimated sport fish or large cruiser wakes, often to my surprise. All wakes do spread out with distance from the origin, so by and large, the wake from a navy Cruiser heading up the Bay at speed will "spread and soften" by the time it gets to me (2 - 3 mile distance) so it feels more like a swell than a wake. I can bob up and down over that but still maintain course and speed. It's the sportfish that make me roll, and leave me feeling stupid for underestimating them. Those wakes, I usually have to make a brief heading correction to get parallel to them. That way, I don't wallow as they pass under me. Jim Peg and Jim Healy, living aboard Sanctuary http://gilwellbear.wordpress.com <http://gilwellbear.wordpress.com/> Monk 36 Hull #132 MMSI #367042570 AGLCA #3767 MTOA #3436