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29./30. Jahresbericht des Deutschen Hydrographischen. Instituts 1974/75 
E. General Report 
THE DEUTSCHES HYDROGRAPHISCHES INSTITUT (DHI) IN THE YEARS 
1974 AND 1975 
Professor Dr. Hans Ulrich Roll who had been President of the DHI since 1965 
retired on 30 September 1974. He was succeeded by Präsident u. Professor 
Dr. Gerhard Zickwolff. 
A decisive step forward was made towards setting up an international coor 
dinated warning system in Northwest European waters: Since 1 April 1975 all 
member states of the North Sea Hydrographic Commission (NSHC) promulgate 
nautical warnings in the RT frequency range six times in 24 hours whilst 
warnings had up to this date only been promulgated three times a day. Early in. 
1976 this improved warning system will also be introduced for the Baltic Sea. 
Moreover, the DHI is actively cooperating in the IHO*} Commission on Stand 
ardisation of Nautical Books which endeavours to improve the safety of inter 
national shipping and to facilitate cooperation by standardising nautical books. 
The 70 or so German nautical books were updated by New Editions or 
Supplements. The number of printed copies of the weekly „Nachrichten für See 
fahrer" was 4100 in 1974, and 4000 in 1975. Numerous Masters and ship's of 
ficers supported the work of the DHI by supplying almost 1000 nautical reports. 
The chart series (comprising about 1000 charts) was further modernised 
and updated. The International Charts produced to IHO Specifications 
proved to be very economical. Thus, by the end of 1975, the DHI had already 
reproduced as many as 25 international small-scale charts which had been pub- 
blished by hydrographic services of other countries; further charts were prepared 
for reproduction. Moreover, North Sea charts produced to international specifi 
cations by Denmark, Great Britain and the Netherlands were reproduced with 
minor modifications. The North Atlantic International Chart Commission 
(NAICC of the IHO) is compiling specifications for medium and large scale 
charts which are to be exemplary for the standardisation of charts covering 
other areas. 
The compilation of charts with overprints of Loran-C lattices was started in 
1973; 28 charts were published in the meantime. This series will be completed 
in 1976 by a further 10 charts. Decca charts are now available for the entire 
Swedish coast up to the Stockholm skerries. The first charts with the Northum 
brian chain were published for the English and Scottish coasts. 
During the two years under review almost 600 000 charts and more than 915 000 
publications (nautical books and periodicals) were distributed. 
) International Hydrographic Organization