Officials said a kayaker might be missing in Lake Jesup. OVIEDO, Fla. – A 47-year-old Geneva man died after his airboat went airborne and overturned Sunday on Lake Jesup in Seminole County, the Florida Fish and Wildlife Conservation Commission said. | Pilot killed in Fla. gyroscope crash]Wildlife officers said a witness was driving north on the S.R 417 bridge and saw a 12-foot airboat go airborne. The witness called over another boat, and the victim was found near the overturned airboat, officials said. The good Samaritans took the man to the Lake Jessup boat ramp in Sanford, where Jelkren was pronounced dead.