Dive with a club or a shop, do refreshers together before a trip, travel as a group of six to twelve who book a boat between them, and maintain contact with people they met on a boat years ago. Dive clubs and shops as the local unit, liveaboard operators' repeat-client lists, certification agency networks, the winter dive shows in Germany and the UK, and trip-specific groups formed before departure.

The liveaboard, a sailing, viz, the safety stop, the surface interval, muck diving, macro versus pelagic, the log, a buddy check, a shore dive, cert card, twinset, a giant stride. Liveaboard departure dates, which are the true editions, plus the January German dive show which is the community's largest single gathering and the point at which many trips are booked.

The destinations have staggered seasons, which keeps the year unusually full. The Maldives and the Indian Ocean peak from December to April.