Somewhere far below sea level, the most fashionable critters in the sub-surface world are gracefully strutting their stuff in form-fitting wetsuits with foot-flattering flippers. Grace the coveted underwater runways of exploration with today's Groupon: for $25, you get a Discover Scuba Diving class (a $50 value) from Dive N Trips in Pleasanton.

A Discover Scuba session lets water-wanderers learn to scuba dive in the relaxing and pleasant environment of a swimming pool. Under the watchful fish-eye of an experienced instructor, divers submerge into a warm-water pool, learning basic techniques and safety precautions while getting a feel for the gear, gizmos, and gadgets. Swimmers will learn to navigate the water in the provided scuba equipment, while also experiencing the tingling sensations that are not jellyfish attacks, but miniature particles of thrill. Each one- to two-hour session is capped at nine submersible students, so instructors can give special attention to each pupil, answering questions and imparting the most effective dolphin-whispering techniques.