Scuba Diving -- In the Desert?

The Blue Hole in Santa Rosa is a scuba diving mecca. The natural, bell-shaped pool is 80 feet deep and has a constant water temperature of 62 degrees. The invitingly clear water (visibility is 80' when undisturbed) in the spring well is produced from a cave system near the well's bottom that generates about 3,000 gallons per minute.

Indeed, there were scuba divers in the Blue Hole...taking classes, I presume.