Jeffrey Hampton of Flint, 31, picks up a second charge of failure to stop and render aid/bodily injury. He remains in Smith County Jail on an $850,000 bond.
Hampton was driving his boat on Lake Palestine, when he struck Hernandez and drove off.
Hernandez was pronounced dead at the scene.
Game Warden Quint Balkcom confirmed that three other people were on the boat with Hampton when he allegedly ran over and killed Roberto Carlos Bermejo Hernandez. Officials took blood to be sent off for a toxicology report. Hampton has previous convictions for DWI and drug possession.
Hampton was arrested Monday by Texas Parks and Wildlife.