The tutorial in the Coastside link has charts included.

"Sal's Dad" wrote in message
...
The only chart I found online is at
http://historicals.ncd.noaa.gov/historicals/histmap.asp ; go to "Entrance
to
San Francisco Bay" 1974 # 5532 - download 5532_1-1974 and zoom in.

Zooming in on the southern end of the bridge, you can see that between
Fort
Point and the South Tower it shoals - from 200-300' in the main channel,
to 30' or so where the capsize occurred. The shipping channel under the
main span stays 200-300'. Once past the bridge, the harbor widens
immediately; presumably the first pier is the one seen in the later
photos.

Sal's Dad

"Calif Bill" wrote in message
nk.net...
A tutorial on the gate and bars on local fishing site. Includes charts.
http://coastsidefishingclub.com/drupal/?q=node/view/58


"Brian D" wrote in message
...

And swells coming in through a narrow channel accelerate through the
constriction. Some won't have been large enough to break, while others
will
be. I think that might be why there's a long period between rollers in
the
picture sequence (of an obviously dangerous place, else why was someone
rushing to get the camera out BEFORE anything bad happened?). Also,
ships
moving through the channel disrupt the swells, or create their own too.

Brian D



"Sal's Dad" wrote in message
...

After looking at many wave photos on this page, I think wave
behavior
in that location is different than I am used to. This place seems
to
have a very long period between waves with nearly flat water
between
them, weird.


Was probably a 10-14' swell day with 13-15 second period. You have
to
remember the waves hitting here have a couple of thousand miles of
open
ocean to build in.


Keep in mind these are not traditional breakers, rolling into a
beach,
but
swells coming through a narrow channel - not very shallow water, but
still
a bar with suddenly shallower depths.

For more info:


http://www.surfline.com/travel/surfm...fort_point.cfm

It appears the tide was coming in, so the boat was caught in one
breaker -
rolled and dismasted - continued drifting under the bridge where the
wash
of a second wave rolled it again, and then into the relatively calm
water
of the bay.