Most tide tables have a corrections factors page requiring nothing more
than addition & subtraction. Even the free tide table we were given last
weekend had this simple system. It's a simplification & will sometimes
be a few minutes off. I can think of 3 things that will trip up shore
bird seekers (or anyone) using these corrections.

1) The corrections page has 5 columns & many many rows. If you're
mostly interested in high-tide time correction highlight that column.
Also highlight locations you are most interested in.

2) Flipping back & forth between the current month page & the corrections
page I usually slip a row or column on one or the other. If you have this
problem, rip out the corrections page & tape it in the back of your field
notebook. That way you can view both pages at the same time. The
correction factors stay the same for decades. But do make sure you use
tables for the correct reference point.

3) At least one Puget Sound & Jaun de Fuca table I use has 2 reference
points. To avoid getting way way off I need to draw diagonal lines
through the pages for the reference point I least use.

Steven S. Coles
Seattle, Washington State, U.S.A.
<scoles at zebu.serv.net>