For listees who don't read the whole article at boatsafe.com which I just posted, here is one section which I found especially interesting: ".. Therefore, in order to classify wave height we determine the significant wave height, which is the average of the highest 1/3 of the waves in a system. This is how weather reports will specify wave height. Average height: 0.64:1 Significant height: 1:1 Highest 10% 1.29: 1 Highest 1.87:1 Some may recall a long e-mail I posted around November/December which I sent to NOAA with a number of suggestions. One thing I did NOT know when I wrote that e-mail is that when a weather report says "3 to 4 foot seas", for example, we should EXPECT some waves 1.87 times as high, almost 6 to 8 feet. For some reason I don't find that large a variation cruising open ocean, but sure do find it in more enclosed bodies of water such as Long Island Sound, NY and Penobscot Bay, Maine,. I attributed those large variations to the combined action of tidal currents and wave motion/direction. Now I'm not so sure. Rob BRueckner Hatteras YF

"Robin" <gymkidd405@netzero.com> At 09:12 AM 3/3/2006 -0500, you wrote: >to NOAA with a number of suggestions. One thing I did NOT know when I wrote >that e-mail is that when a weather report says "3 to 4 foot seas", for >example, we should EXPECT some waves 1.87 times as high, almost 6 to 8 feet. As usual this subject begs for clarification. A few points which I hope will help. Not only are there a few waves 1.87 times as high as the average, but there is about a 1 in 2000-4000 chance of a wave 3 times the average height. But, note that these statistical chances are estimated from mathematical equations and these equations just happened to have been a "good" fit to the data that was used in the study (s) that established all of these so called "rules". Some day, someone will produce an equation which better describes the data and that will become the new standard. In other words, the numbers are useful tools, but we use them in lieu of anything better. Not because they are THE definitive description of the real world of waves. For instance, in any given storm there is a unique pattern, which will vary slightly from the equations. If you had access to the raw data from the weather/wave buoys you could use that data to try to identify the uniqueness. The weather service doesn't generally do analysis or reporting to this level of study and if they did, it is not clear that the boating community would appreciate or put it to effective use. There are a lot of people writing about this subject due to the fact that there are so many published studies and books from which to glean some insight. Keep in mind that there are rehashes of material, which may, but is not likely to advance the understanding of waves. And, there is other analysis, which consists of extensive real world experience, coupled with a study of the relevant papers and from which occasionally some real advance in the understanding of waves, is derived. There is little harm and reading all of these materials, rehashes and the really good "stuff". Just keep in mind that there is a difference and no one understands waves completely. It is really tragic that William G. Van Dorn who wrote Oceanography and Seamanship and had all of the great qualities needed in this subject: analysis, extensive seaman's experience and was a gifted writer is no longer able to contribute to the conversation. Mike Capt. Mike Maurice Tualatin(Portland), Oregon