The D'Iberville-class ships were a development of earlier torpedo cruisers, with the chief improvement being a significantly higher speed.

The ship's propulsion system consisted of a pair of quadruple-expansion steam engines driving two screw propellers.

The ships conducted a simulated bombardment of the port, neutralized the coastal defenses, and put some 6,000 men ashore.

Cassini and the coastal defense ships Bouvines and Amiral Tréhouart were subjected to a simulated attack by the submarines Morse, Narval, Triton, Espadon, and Français.

Cassini was able to evade an attack from Morse, but in doing so, came within range of Français, and was judged to have been sunk; both coastal defense ships were also ruled to have been destroyed by the submarines.

[19] On 2 April, Cassini and several other vessels steamed to Cherbourg, where they welcomed a visit from the British King George V aboard his royal yacht Victoria and Albert three days later.

[21] She took part in the fleet maneuvers for 1906, which began on 6 July with the concentration of the Northern and Mediterranean Squadrons in Algiers in French Algeria.

The maneuvers were conducted in the western Mediterranean, alternating between ports in French North Africa and Toulon and Marseilles, France, and concluding on 4 August.

[23] In July 1908, Cassini joined a flotilla of vessels that included the new pre-dreadnought battleship Vérité for a tour of the Baltic Sea and a visit to Russia.

President Armand Fallières traveled aboard Vérité for the trip, and Cassini formed part of the escort, which also included the armored cruiser Dupetit-Thouars and the destroyers Baliste and Arquebuse.

The ships cruised north to Dunkirk, where Fallières embarked on Vérité, and then continued on into the Baltic, stopping in Copenhagen, Denmark and Stockholm, Sweden.

[25] From then through mid-1915, Cassini patrolled the Strait of Otranto and off Corfu at the southern end of the Adriatic Sea with the rest of the main French fleet.