[talk-au] Mapping Coastlines (Was: Re: Boundary removal.)

[Andrew Harvey]

On Sat, Feb 4, 2012 at 4:00 AM, David Groom <reviews at pacific-rim.net> wrote:
> That will depend on the gradient of the land between the highest high water
> spring tide, and the lowest high water spring tide, and what location you
> are in, since the tidal variation between spring and neap tides varies
> enormously depending whereabouts you are.
>
> I think you are possibly seeking a higher degree of accuracy than is
> required.  Also then next question would then be to concern ourselves with
> whether we took the peak water point of the largest expected wave, or the
> average wave.

I think you are right, I'm probably trying to get too much detail.

The point I was trying to make was I thought mean high tide was
supposed to ignore the effects of waves. Perhaps though for OSM in
lure of more accurate details, the highest wave would do as a
coastline...

On Sat, Feb 4, 2012 at 12:45 PM, mick <bareman at tpg.com.au> wrote:
> Is there not an Official Datum for tide heights, I vaguely remember reference to it in a project I was involved in back in the early 1990's.

Then we would still need the contour for that height.