Right weight for your suit and salt/fresh water.
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BCD (buoyancy compensator)Cressi Travelight and Scubapro Hydros Pro are the two benchmarks. A jacket-style BCD is easier to learn in; backplate/wing comes after you're comfortable.
Scuba regulator setScubapro MK25/A700 and Cressi AC2 are reliable first/second stage combos. Buy new — used regulators require full service before trusting at depth.
Dive computerSuunto Zoop and Garmin Descent Mk2 are the two common choices. Any dive computer beats tables for real diving. Check algorithm conservatism if you fly frequently.
Wetsuit (3mm full or shortie)3mm full suit covers most tropical and temperate diving. Bare, Cressi, and Henderson have consistent sizing. Size tight — it will stretch.
Mask and fins setCressi Ranger or Mares X-Vision for mask (low-volume is easier to clear). Scubapro Seawing Nova or Cressi Frog for fins — split fins for comfort; blade fins for power.
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