After studying at the École Polytechnique and qualified as a marine engineer before starting work at the Toulon Naval Yard in southern France.

That same year he started work on Morse, a submarine of his own design, intended to combine the best features of both previous vessels.

In 1903 he oversaw the construction of the Naïade class of submarines, a set of 24 vessels built over a two-year period at Cherbourg.

Romazotti favoured a single-hulled form, as opposed to the double-hulled submersible pioneered in France by Maxime Laubeuf, which brought the two men into conflict.

[1] Romazotti also used a copper alloy of his own devising, called Roma-bronze, which was intended to give a submarine's hull more flexibility than an all-steel hull, and which would interfere less with the use of a magnetic compass.