On Sep 10, 3:22?pm, Wayne.B wrote:
On Mon, 10 Sep 2007 14:28:39 -0700, Chuck Gould

wrote:
That's a bit funny- but I think the photo of the Ditmar Donaldson
punching through that surf *does* serve as a good reference for wave
height. The USCG review of the incident reportedly refered to that as
a "20 foot" wave. A legitimate 8-footer would still be 40% as large-
so I do try to bear that in mind when I hear boaters describing rather
extreme wave heights. Most people routinely overstate wave height- at
least IMO formed by years of observation. No need, really; 4-5 footers
can make for some really challenging conditions when expressed as
short interval chop.

All true but that's not just any old 20 footer of course. The fact
that it is steep and breaking is what causes all the excitement.

Precisely. Spread that same 20-foot rise out far enough and you have a
nice, gentle swell. Very few of the "white knuckle" tales involve
gentle swells. A 4-footer breaking on the beam will put my side decks
awash,
and a breaking 6-foot head sea will put green water on the foredeck.
Nope, nope, nope- don't need to do that when it can be avoided, and
just short of all of the time it can be when coastal or inland
cruising.

A lot of the coastal harbors in WA, OR, and CA have river bars. the
combination of rapid shoaling, an onshore wind, and conflicting tides
and river currents can create some very nasty conditions. In many
locations, the USCG literally closes the bar to navigation when
conditions get ugly enough. One of the reasons for "surfman" training
is to prep the Coast Guard personnel to perfrom rescues of folks who
don't heed the "closed bar" warnings.