Check your dive shops down there. I have a buddy up here that can train you for $150. We went down and dove the San Marcos river last night! Great night dive! Put in at Joe's Crap Shack and drifted just before the falls. It was a good 1 hour and 45min dive. Lots of fish and interesting dive. Only hit about 11 feet deep but a good dive anyway. Visability was a good 30 feet but hard to tell with a dive light. Probably more. Near the end of the dive though it got murked up from all the feeder streams.