Ascent Rate – The rate you go up from your dive.. max 18 m/min.Artificial Reef – Man made constructions, for corals to attach themself tooApnea Diving – Breathhold diving, free diving, you dive with out scuba equipment on a single breath down.
Aluminium Cylinder – The material used in thailand and other hot environments. Corrode less than steel and the tanks are lighter.
Altitude Diving – Diving taking place at 300 m or more above sealevel.
Alternate Air Source – an extra airsource, used for your buddy in emergency. Also called the octopus.
Air Composition – The composition of gasses in an airmix. Normal air-21% oxygen, 79% nitrogen.
Advanced Diver – A diver who has taken the advanced open water course.
Bar– You measure pressure in Bar or atmospheres.Barotrauma– Pressure injuries.
BCD– Boyancy control device. The jacket that controls your Boyancy and keeps you scubaunit together.
Buddy Check– A predive safety check done together with your buddy.
Buoyancy– Your position in the water. Neutral: when you neither sink or floats, positive: when you float, Negative: when you sink
Burst Disk– A safety device on your tank that will release pressure from the tank if it gets overpressurized.
Breath Hold Diving– See apnea diving.
Bottom Time– The time from you descent till you are back on surface again.
Balanced Regulator– When your regulator is not effected by surrounding pressure or tank pressure. Same resistance through the whole dive.