There is a version about the constructing of the tide-gauge «on walls» of Peter and Paul fortress after Neva flood in 1715. But the foundation of this version is the brief fragment from I.G. Georgi’s opus (1790). It isn’t clear from the translation of original text what fortress is mentioned – Peter and Paul or Admiralty. At first sight this text can be associated only with «Peter and Paul version». But impossibility of finding references of sources which can verify the existence of first Russian tide-gauge near Peter and Paul fortress from 1715 (by decree of Peter I) and inconsistency of these statements with wellknown facts are the reason not to formulate precipitate conclusion.
Many facts confirm «Admiralty version»: establishing of department – prototype of «Admiralteistv-College» (with functions of level monitoring); provision of safety launching of vessels; special attention of Peter I to marine attributes (foreign experience implied tide-gauges in ports). Besides no one document which verifies the organization of first instrumental researches of natural environment in Russia and which dates earlier than I.G. Georgi’s opus contains mentions of the Peter and Paul tide-gauge.