I can't speak specifically to Murrelets there, but in kayaking around
the San Juans, I've observed the following:

-feeding birds sometimes focus on turbulent upwellings and eddylines
where baitfish will have difficulty maintaining a protective school.
-birds are more likely to be resting during periods of slack (low)
current.
-what I would call a weak eddyline forms N of Green Pt. on the ebb and
flood currents. Birds feeding in this area would be within scope
range of Washington Park.
-weak, diffuse turbulence occurs SW of Green Pt. near the entrance to
the passage between Fidalgo Island and Burrows Island. Birds feeding
in the current *might* be within scope range of Washington Park.
-Strong turbulence forms far W of Green Pt., closer to Bird Rocks over
the large shoal E of Bird Rocks. Birds feeding in this current will
not be visible from Washington Park.

If birds are resting near Green Pt., you would probably do best around
times of slack current. If birds are feeding near Green Pt., you
would probably do best around times of peak current. These times are
typically 3 to 4 hours apart, so visit at the first convenient slack
or peak time of the day, and if you get skunked, go elsewhere (e.g.
Samish Flats, Bayview State Park if tide is high) for a couple of
hours and come back.

Times of slack current do not necessarily correspond to high and low
water times. Usually they're close, but in some places the difference
can be large. You can look up the current predictions here:
http://tidesandcurrents.noaa.gov/curr_pred.html
or here
http://tbone.biol.sc.edu/tide/index.html
The Xtide server has a new map-driven interface, but the database of
lat./long. coordinates still has some errors: note the cluster of
sites inside Olympic National Park. (These errors don't affect the
current data, just the plotted location.) If you can't find the right
site, try a text search on the text-based list of West Coast sites.
There *is* a site for Green Point, but the Rosario Strait site is good
enough, since the timing is pretty close.

Mike Wagenbach
Seattle

Wheee!
http://www.youtube.com/watch?v=YXRH50fvHWA