=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 27-Aug-1997
The site of the tide gauge is subject to subsidence.  During the period 1929-95 the datum of observations has sunk 0.244m
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 10-Mar-1999
For a discussion on sea level trends along Black Sea coasts see Variations of the Black Sea Level by S.G.Boguslavsky et al., Physical Oceanography, 9(3), 199-208, 1998.
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 10-Mar-1999
Bulgarian sea levels likely to be heavily influenced by river flow.
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 10-Mar-1999
In March 1999 a 'buddy checking' on the following 6 Black Sea stations in the RLR data set in order to check out some apparent west-east differences in the MSL values:
295021R Bourgas     Bulgaria
295051R Varna       ..
297021R Constantza  Romania
300001R Tuapse      Russia
305021R Poti        Georgia
305031R Batumi      ..
It seems that Varna, Tuapse and Batumi seem basically 'ok' except that after about 1985 Tuapse and Batumi start to increase relative to Varna. The increase of Tuapse is about 10 cm relative to the western ones, that of Batumi is more like 20. Bourgas compared to Varna seems 'ok' as well except there is a period around 1950-55 when Bourgas is relatively low by about 8 cm. Also Constantza is ok relative to Varna if a large dip in Constantza around 1980-85 and a datum shift around 1948 are taken out.  Tuapse minus Constantza shows the rise from about 1985 again. For Poti, it is very hard to see what is going on given the large background trend. It has a clear large fall in 1960's though. real? And as Tuapse and Batumi have different increases relative to the west presumably the effect is in the east?  Are there levelling (datum) concerns we are not aware of?  Recent changes to local rivers?
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 25-Jan-2000
Bourgas             295/021 RLR(1995) is 11.5m below BM no. 12
Bourgas is an historic station last data 1996.

