CLAY COUNTY, Fla. -

A 51-year-old Jacksonville man was seriously injured after diving off a dock at Kingsley Lake in southern Clay County on Thursday afternoon, according to the Clay County Sheriff's Office.

Deputies and Fire Rescue crews were called to the scene just before 4 p.m. after Scott Hamner dove in the water and didn't surface.  Family members pulled the man from the water and performed CPR until emergency workers arrived.  Hamner was taken to a hospital in Starke, where he was stabilized and transferred to UF Health in Gainesville for in serious condition.

Authorities say family members are with him at the hospital.