He was the second husband of Princess Caroline of Monaco; he died during a racing accident defending his 1990 Class 1 World Powerboat Championship title.

[3] A throttle man,[8][6] a role that requires control of the trim tab while observing water conditions to reach optimum speed, Casiraghi participated in eighty offshore races during his lifetime.

[6] On 29 December 1983 in Monaco, he and Princess Caroline married in a civil ceremony in the Hall of Mirrors of the Monegasque Princely Palace.

The children were born at Princess Grace Hospital Centre in Monaco, respectively, fourth, eleventh and eighth in the line of succession to the Monegasque throne, after their twin cousins and their mother.

Races now take place close to the harbour where waves are gentler, which is policed off for safety reasons as boats are no longer allowed to drive near the course.

Of the accident, Anne Edwards wrote that Casiraghi and his copilot, Patrice Innocenti, had been "trying to make up for time they had lost earlier in the race when they had stopped to rescue a pilot whose vessel had caught fire.