There's a moment most divers recognize. You've done enough dives to know that rental gear is okay, but it's just that—rental gear. It’s not yours. However, from a technical standpoint, buying your first regulator can be daunting.  The Cressi AC5 / Zen is designed for recreational divers and first-time buyers with two clear objectives: to offer consumers a regulator that breathes well and is easy to maintain. We tested it on dives in both cold Danish waters and the warm...