X-Ray, an excellent (and free) online magazine oriented towards diving and underwater photography, has just announced the availability of issue #15:
Travel Mexico’s Riviera Maya—Discover the secrets of the ancient Mayan underworld as we explore the cenotes of the Yucatán. Another adventure takes us to the deepest cave in the world—Voronya Cave of the Caucasus.
We also take a closer look at Regulators. How do they work, what to look for when buying a new regulator, how to avoid and handle free flow. And much, much more!