What was done
The author was primarily concerned with forecasting how much the southern Baltic Sea might rise by the end of the current century.  We, however, are more interested in what the data of the past century reveal.

What was learned
Based on data from 1901-1990, there was a linear increase in mean annual sea level at Kolobrzeg of 12 ± 2 cm per century.  Over this same period, however, there was no trend in annual sea level maxima.  Two high values stood out above the rest in the 1980s, but two similar spikes occurred in the 1940s; and there were half a dozen comparable high values in the first two decades of the record.

What it means
The author's analysis of the mean annual sea level data for the southern Baltic seaport of Kolobrezeg yields results that are compatible with the results of most other such studies that have been conducted.  The author notes, for example, that "neither in the world ocean nor in European seas (Woodworth 1990, Gornitz & Solov 1991, Douglas 1992) has there been any acceleration in sea level rise in the 20th century."

Superimposed upon the slow upward trend in mean sea level, it is surprising that annual maximum sea levels due to storm surges have not risen over the past century.  One can only conclude these events have become less intense in recent years (and possibly less frequent).

References
Douglas, B.C.  1992.  Global sea level acceleration.  Journal of Geophysical Research 97: 12,699-12,706.

Gornitz, V. and Solov, A.  1991.  Observations of long-term tide gauge records for indicators of accelerated sea level rise. In: Schlesinger, M.E. (ed.) Greenhouse Gas-Induced Climatic Change: A Critical Appraisal of Simulations and Observations.  Elsevier, Amsterdam, pp. 347-367.

Woodworth, P.L.  1990.  A search for acceleration in records of European mean sea level.  International Journal of Climatology 10: 129-143.