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Frank wrote:

> He mentioned  a shoreline where it's very difficult to get down to
the
> water's edge.

At least not without some lightweight mountain-climbing (and maybe
rappelling) gear... that's a little overkill in my book just to grab a
few practice sextant shots when all I want is a good sea horizon...
;-)

> Picture,  for example, a road running along a rocky shore. You're
> maybe 20 or 30 feet  above the water level, and there's a jumble of
> boulders below you leading down  to the water.

In that case, I estimated the height of the roadside based on nearby
houses actually on (and over) the beach. One had a concrete
foundation/porch combination that came just about level with the road -
it looked taller than a standard 8' room ceiling would be, so I called
it 10' + 6' for my height of eye for 16' total. I got sight accuracies
under a mile with that guess, so I suppose it was at least close. Next
time I hit that spot I think I'm going to take along a tape measure and
see what it really is.  :-)

In another location, the shots were taken from a beachside parking lot
- I estimated the He on that one by walking down to the water's edge
and noting that my eye lined up just about exactly with a doorknob on a
building in the parking lot, then standing alongside of it and figuring
the rest of the distance up to eye-level. The things we do to get
accurate practice sights...  ;-)

--
GregR


> Alex wrote:
> "I don't see any problems with  height of the eye when observing
> on a beach:-) Just stand or sit on the edge  of water and know your
> own
> height, standing or sitting."
>
> He mentioned  a shoreline where it's very difficult to get down to
> the
> water's edge. Picture,  for example, a road running along a rocky
> shore. You're
> maybe 20 or 30 feet  above the water level, and there's a jumble of
> boulders below
> you leading down  to the water.
>
> "If you cannot approach the water edge, go as close as you  can,
> and estimate the rest by eye. This gives you 1 ft precision
> in most  cases."
>
> Ok. And how do you confirm that? For some people it may take
> practice to
> develop that ability to "estimate the rest by  eye".
>
> -FER
> 42.0N 87.7W, or 41.4N  72.1W.
> www.HistoricalAtlas.com/lunars
>
>
> >
>


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