History of Tidal Research in the Baltic Sea

When tidal predictions in the form of tables did not yet exist, a local time, the so-called establishment of the port, was used for nautical purposes. Once the establishment of the port has been determined precisely for a particular location, all that is needed is an Astronomical Almanach listing the culmination times of the moon for each calendar day, and the times of high tide can be computed easily with a precision of about 1 h.  

Consequently, Friedrich Pasc hen (1804-1873) included the culminations of the moon in his water level analyses at the Wismar gauge station (Paschen, 1856) in order to prove the existence of Baltic Sea tides. His primary goal was to clearly disprove the widespread notion that the ebb and flood tides are not noticeable in the Baltic Sea. This was also supported by the observation that, with constant wind conditions, the mouths of rivers discharging into the Baltic Sea could be observed to alternate several times a day between inflow and outflow. 

The next milestones in tidal research were two papers published by Hagen in 1858 and 1860 as part of a series of mathematical treatises issued by Konigliche Akademie der Wissenschaften (Royal Academy of Sciences), Berlin. The decisive advance over Paschen was his complete coverage of the coast from Travemiinde to Klaipeda and the availability of hourly gauge data for some areas. Hagen s findings can be summarized as follows  

On the international level, these activities were continued within the framework of the European Arc Measurement, when the riparian states were requested to install measuring instruments on as many coastal points as possible in order to determine the mean sea level 

Seibt concluded from a comparison with establishment of the port data from Danish 

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