SSI Advanced Open Water (or 5+ logged dives). Age 15+.

Yes, every dive uses conservative limits, redundant air, and your instructor is at arm's length on dive 1. Deep diving is risk-managed, not risk-free.

At 30–40m, your bottom time on regular air is very short (10–15 min). Nitrox extends it to 18–22 min, much more useful for actually seeing the wreck/wall.

You'll experience mild narcosis on the deep dives, that's the point. Your instructor monitors you, runs a memory drill at depth, and you ascend if anything feels off. The skill is recognising it, not avoiding it.

Tell your instructor immediately, we abort the dive, ascend slowly, regroup. Ear injuries are 100% preventable if you stop on the way down. We'd rather do dive 2 of 4 than push through pain.

Digital cert via the MySSI app at the end of dive 4, same day. Show it on your phone at any dive centre worldwide for the rest of your life.