Thread: Wave heights
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JAXAshby
 
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Welcome back, Roger. Glad to have you here. Wait around a bit and hoary will
tell you of the 40 foot waves menancing Annapolis.

I've been kind of interested in some of the posts about Lake Erie conditions
to see references to 12 foot waves. I know the waves are shorter and steeper
there due to the lighter water and shallow depths. Twelve footers would
considered pretty big however, even on the ocean.

I've been pretty involved in past years with marine safety and accident
investigation projects and this gave me a chance to look into wave height
reports. There is a pretty consistent tendency for even experienced seaman
to over estimate wave heights by about 100 percent.

There is a way to estimate wave height with fair accuracy. I've done it and
then looked at what I know to be six foot waves a minute or two later and
still been unable to convince my brain that I was not looking at twelve
footers. There are some physical as well as perceptual reasons for this.

For reasons that are more psychological, there is also a tendency to
overestimate heel angles by about the same proportion. This has influenced
accident investigations when observations have been accepted as fact.

If you'd like a good sea story, and to get some idea where I'm coming from,
read "Pride of the Sea" by Tom Waldron. My name pops up frequently through
this story of the loss of the "Pride of Baltimore."

A drier, but in some ways more technically interesting book is, "Tall Ships
Down" by Daniel S. Parrott. I also have a couple lines of page numbers after
my name in the index of this book and was involved in the post mortum of
three of the five accidents discussed.

If you saw the History Channel "Deep Sea Detectives" show about the sinking
of the ship that took Admiral Byrd's aircraft to Antarctica, you also saw me
at the end discussing her loading and stability.

I just mention these things because I'll be pretty active in this news group
now that I'm getting back into sailing and cruising and people may as well
know who I am.

--

Roger Long