11 meters checks out, I checked it via: https://www.daftlogic.com/sandbox-google-maps-find-altitude.htm#

There's no issue with the hight above mean sea level of King's Road, Brighton.

To make it clear again: This PhD did not take into account the different reference systems for "land charts", which is "mean sea level" and for "sea charts", including tide tables, which is LAT - "lowest astronomical tide".

Just to explain it a bit different: The hight of the traffic lights above mean sea level is ok. But observers hight or actual water level hight is wrong. The tide tables do not give the hight above mean sea level but above LAT, which is about 3.75m below mean sea level!

(you could calculate an approximate value from msl from the average of one high water and the following low water from the tide tables)

PhD puts observers hight at 1.34m above mean sea level. All yachtsmen at Brighton Marina and any uneducated fisherman would shake their heads for disregard, if you declare actual water level hight during a Low Water is

**above** mean sea level.

So actual water level hight and so observers hight is not 1.34m above mean sea level, it is below mean sea level, about -2.4m! (1.34m-3.75m)

Which in total changes hight of the traffic lights above the observer to about 16m (the value calculated by PhD + 3.75m) - Which is the predicted value from Globe Earth curvature calculator.