haydenfox!#$ wrote: »
Are the depths listed on Vavionics, NCEarth, Hot Spot charts, etc high tide, low tide or an average depth?
Capt M Brennan wrote: »
Chart depths are represented by the Mean Low Water (MLW)
From NOAA, "The average of all the low water heights observed over the National Tidal Datum Epoch. For stations with shorter series, comparison of simultaneous observations with a control tide station is made in order to derive the equivalent datum of the National Tidal Datum Epoch."
Which is pretty much Greek to me, I just know that chart depths are measured from Mean Low Water and bridge heights are measured from Mean High Water.