Scuba Diving International (SDI) AFS 270 Practice Test

The main idea here is a quick safety check that focuses on three essentials before the dive: air supply, buoyancy control, and the dive computer. The best answer matches Air On, BC Inflated, Computer Checked And Activated because you first verify the gas is available by turning the tank valve on and confirming you can breathe from the regulator. Next, you ensure the buoyancy control device is inflated so you can control buoyancy from the start and to help spot any BC leaks. Finally, you turn on the dive computer and verify it’s functioning and configured (correct mode, alarms set, and gas settings) so you have accurate depth, time, and decompression information during the dive. The other options mix in items not part of this acronym and, in some cases, suggest unsafe or irrelevant steps (such as Air Off or BC Deflated at the start, or a compass or a nonstandard item like Cycle Verified).