Yes — South Carolina Reg 61-51 requires a telephone accessible to the pool deck capable of dialing emergency services.
South Carolina requires a telephone accessible to the pool deck that is capable of dialing emergency services.
Citation: Reg 61-51
As with several other states, South Carolina's rule doesn't specify an exact distance, so the phone should be reachable from the pool deck without unlocking gates or unreasonable delay.
SouthEast Telephone installs and monitors cellular emergency pool phones nationwide and can help you meet South Carolina's requirements.