V1 WAS OPERATED NORTHBOUND ALONG THE BONEY MARSH SLOUGH PORTION OF THE KISSIMMEE RIVER. V1 WAS ON THE HIGHLANDS COUNTY SIDE OF THE RIVER, TRAVELING APPROXIMATELY 5-10 MPH. V1 OPERATOR APPROACHED A LARGE OAK TREE GROWING OUT OVER THE CREEK BED. V1 OPERATOR MANEUVERED THE AIRBOAT DIRECTLY UNDER THE EASTERN OUTER EDGE OF THE TREE BRANCHES. THE PORT SIDE AIRBOAT CAGE MADE CONTACT WITH A LARGE TREE LIMB CAUSING THE BOW OF THE AIRBOAT TH JERK PORT IN RETURN CAUING THE PASSENGER SITTING IN THE REAR SEAT TO RECEIVE EXTENSIVE HEAD INJURIES FROM THE TREE LIMB. AFTER THE LIMB PUNCTURED THE CAGE MESH, THE LIMB MADE CONTACT WITH THE PROPELLER CAUSING THE PROPELLER TO SHATTER AND EXPLODE IN DIFFERENT DIRECTIONS THROUGH DIFFERENT PARTS OF THE CAGE AND METAL WORKS.