Isham was leading a group of student divers at Makole Reef on the Na Pali Coast, when one of the students lost control of his buoyancy and began floating toward the surface. Isham chased after the student and was trying to bring him back down when a passing tour boat ran over them. The boata¿¿s propeller cut into Ishama¿¿s leg in four places while also gashing and breaking the student's right arm. Both men were pulled from the water and received immediate medical attention, but Isham's leg had to be amputated above the knee.

A special fund has been created to help Isham and his family. Divers who would like to donate or learn more can do so at www.mattisham.com.