Welcome to Scubaboard.
If you are interested in ocean diving, contact Scuba Express in Murrell's Inlet (about 3 hour drive from Columbia).
In Columbia, contact Wateree Dive Center. Lake Murray is near Columbia, but I'm not sure if there is anything to dive on there.
For black water diving (and treasure hunting), the Cooper River is popular. Check out Underwater Adventures in Sumter SC - they dive the Cooper a few times each summer, and know others.
For lake diving, Clarks Hill (AKA Lake Thurmond) is on the SC/GA border. Contact Neptune Dive and Ski in Augusta GA for information, or hook up with Diveprof here on SB via Private Message.
If you are interested in diving the warm water produced by a nuclear reactor, contact Upstate Scuba - they dive Lake Jocassee frequently and can recommend locals to dive with.
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