=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 24-Jan-2017
Porvoo is a new Finnish station with data beginning in August 2014.
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 27-Nov-2019
From 2018 onwards the averages of the Finnish sea level data will be based on 1 min observations. Values are calculated in Finnish normal time (EET).
The data are relative to the reference surface of the Finnish sea level observations and thus the datum is the tide gauge zero.