=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 02-Feb-2016 Port Isaac is a new station operated by the Channel Coastal Observatory (CCO) based at NOC Southampton. Istrument type is an Etrometa Step Gauge. The datum of the data is Admiralty Chart Datum (ACD) 11.515m below TGBM. Tide Gauge Zero (TGZ) is 3.970m below ODN and 0.170m below Admiralty Chart Datum (ACD). TGZ is alo 11.685m below the Primary benchmark TGBM. Sampling interval is 10mins.