It was the wrong day for Stephen Bogaerts to have forgotten his wet suit, but forget it he had. What followed this realization was a manic drive back to the diving center, then a hurried leap into the water. The hour-long delay turned out to be fortuitous. His diving partner, Robbie Schmittner, was swimming downstream from a different starting point, carried by a current that Bogaerts would be fighting on his opposite path.
Normally the current rages, but on the day in question, January 23, 2007, it was unusually gentle. So Bogaerts reached the rendezvous point a half hour sooner than expected, and Schmittner 20 minutes later. As Schmittner turned the last corner, he saw Bogaerts’s light flickering in the distance. The ethereal glow marked the juncture of two giant caves—Sac Actun and Nohoch Nah Chich. With their discovery of the opening, the divers had proved that the two caves were really one, now called simply Sac Actun.
At the time, that made it the largest known underwater cave in the world, with almost a hundred miles of passages charted. Schmittner dropped a bottle of Moët & Chandon champagne to the cave floor to mark their arrival at that special juncture in one of the world’s greatest (yet least heralded) natural wonders.
Sac Actun: The Largest Underwater Cave in the World
For Schmittner and Bogaerts, the exploration is never done. After they discovered the Sac Actun connection in 2007, another Yucatán team showed that the underwater cave Ox Bel Ha, at 170 kilometers (106 miles), was longer still. But the race for the longest is not over. Recently Schmittner and Bogaerts were excited to learn that Sac Actun lies within 18 feet of Dos Ojos, another cave system.
