A tide gauge carved in stone, calibrated in Parisian feet and inches, and probably dating back to 1785, can still be seen on the right bank below the Ponterosso (Red bridge).
The Zero of this gauge, known as "Zero Ponte Rosso", marked the level of low tide throughout the former Austro-Hungarian Empire.
However, from 1875 a hydrometric station built for the Maritime Government was used as a reference for the whole Empire, including Serbia and Montenegro. Its management was entrusted to the Commercial and Nautical Academy, located in the Casa dei Piloti (The Pilots' House)on the jetty, before the construction of the present Yacht Club Adriaco headquarters at the end of Sartorio Pier.