If the user feels vibrations whilst flying, it is not cavitation, but they affect the performance, comfort and may damage mechanical parts on Flyboard® and the PWC. If the vibration problem is solved, performance will be improved.
1st Step you need to try is to remove nozlles.
2nd Step: If the problem continues, replace the wear ring of the u-pipe with anti vibration system. Comes as a set of four (4).