Since I'm the one what caused most of the confusion and gave the most
bad info, let me try an example to hopefully clear up the mess.


Your tide datum is MLLW (also called Zero tide)
On your chart you have a box showing tidal data.
In this box, MHW is listed as +6.0'; MHHW is listed at +7.0'.
You are on a sailboat approaching a bridge. The height at your present
draft to the tip of an antenna at the masthead, is 50'. The clearance of
the bridge shown on the chart, is 50' at MHW.
AT Zero tide (MLLW), you will have 6' clearance between your antenna and
the bridge. At +6.0' tide (MHW), you will hear a slight "Ping" as the
tip of your antenna touches the bridge. At any stage of the tide which
your tables show to be greater than this (+7.0,8.0,9.0, etc.) your next
stop will be the nearest boatyard for repairs.
At any stage of the tide where the numbers show a minus reading (below
MLLW) you will gain additional clearance.

All warnings about accuracy of tables and predictions based on possible
weather, etc. conditions, still apply.

BG

otn

PS got my hands on a light list .....no tidal info in there for
particular lights, that I could see.