MHW is very important on US charts. RB might hurt himself trying to figure out why -
should we give him a hint?

As to your other question, yes the Chart Datum for Soundings is not absolute, it is
relative to the local tide. Usually not a factor, but if you're looking at a chart of the
Cape Cod Canal you have rather different tide domains at either end - a 10 foot range on
the CC Bay side, about 3 feet in Buzzard's Bay - hence a rather severe current.

-jeff
"There is a tide in the affairs of men / Which, taken at the flood, leads on to
fortune." - William Shakespeare


"Donal" wrote in message
...

"The_navigator©" wrote in message
...
Right, but those are not entered on a chart are they?


MHWS & HLWS? No, they are not mentioned on the chart. I've just checked
one of my charts, and it explains that CD is "about" LAT - but, it doesn't
say where??? I wonder if that means that there are multiple CD's for a
chart that covers a 50 mile stretch of shoreline?

On the back of the chart, they have printed all sorts of useful information,
including definitions of MHWS, MHWN and MHW!!!

I don't remember learning about MHW, and I cannot think of any practical use
for the figure.

Perhaps Bob can explain what use one could make of the MHW figure??

Regards

Donal
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Cheers MC

Donal wrote:

"Scott Vernon" wrote in message
...

Yes, those of us with a functioning brain knew that. I believe that
charted depths are given at MLW and it's up to the sailor to know the
tide
table and apply it. Maybe that's why that site gave it that way?

Scotty


Around here, heights are given above chart datum, which is traditionally
the
same as LAT. This can vary from one port to another. Today, at Low
Water,
Portsmouth will have 2m (6'6") above CD.


http://www.portsmouth.co.uk/ViewArti...rticleID=55658
2


Also, we have MLWS, and MWLN but we don't have a plain MLW.


Regards


Donal
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