The craft capsized between Doolough and Claggan in Blacksod Bay but Ballyglass RNLI responded rapidly.
The volunteer lifeboat crew launched the lifeboat from Shore Road Belmullet within 10 minutes and were on the scene within half an hour in favourable conditions.
A rigid inflatable power boat in the area had taken the casualties aboard until the lifeboat arrived. Once on scene, the lifeboat crew took the uninjured jet ski crew aboard and proceeded to bring them safely to land at Doolough.
No medical assistance was required. The Ballyglass Coast Guard unit was also tasked to assist.