GL: Pressure waves in the water

[Rich Gano]

I don't think there is any real disagreement here, John.  If somebody ahead
of you kicks up something big you cannot see, well, it's your turn.  But I
still think a lot of the floating junk a fast boat will run into is easily
pushed aside at slower trawler speeds - certainly not all.  But even
something big has a chance to be "bounced" clear of running gear if first
contact is with the hull, and the hull is hitting with a lot less force and
thus less likely to suffer penetration.
  -----Original Message-----
  From: Truelove39 at aol.com [mailto:Truelove39 at aol.com]
  Sent: Thursday, November 22, 2007 7:24 AM
  To: richgano at gmail.com
  Cc: great-loop at lists.samurai.com
  Subject: Pressure waves in the water


  Hi Rich-

  Not to be argumentative, but you might be interested in a story related to
me by James Taylor of AYB about 10 days ago:

  Awhile back, many boats were getting their running gear torn up in the
Chesapeake and Albemarle Canal upon getting up to semi-planing speed after a
slow stretch. But others were not. Soon, it was realized that the boats to
increase speed were getting away unscathed, while those which followed
suffered damage. Turns out there was a waterlogged tree in the middle of the
canal, and the "suction" of the first two boats was "pulling" it upward
where it was then repeatedly struck by those behind. Whether this was
"suction" or a reflected pressure wave is neither here nor there, but the
fact that it happen(s) is. This was not the first instance of this scenario,
nor will it be the last. Although speed was the culprit in this case, worse
is to follow a tow closely, anywhere in shallow water.

  Just my .02

  Regards,

  John
  "Seahorse"


  > I wouldn't worry too much about the ICW having trawler-sinking debris
  because at trawler speed, the buoy that 50+ footer yacht hit going "22
knots
  an hour" is probably more likely to be pushed away by the boat's pressure
  wave with a lighter strike than that speedster got.







----------------------------------------------------------------------------
--
  Check out AOL Money & Finance's list of the hottest products and top money
wasters of 2007.