Guides
How certification levels line up across PADI, SSI and CMAS, what each course covers and how to pick the next one.
Course content and prices differ between dive centres. These guides help you know what to ask before you sign up.
Training & Certification9 min read
PADI, SSI and BSAC diver cards never expire. Pro ratings, first aid training and medical clearance can lapse. Dive centre gap rules and lost card replacement.
Read moreTraining & Certification8 min read
How a dive computer tracks nitrogen, what NDL means, what counts as a repetitive dive, and what to do after an overstay, a failure or before a flight.
Read moreTraining & Certification9 min read
What CMAS One, Two and Three Star divers may do, which PADI and SSI courses sit closest to each star, and the depth limits your card carries abroad.
Read moreTraining & Certification9 min read
Pressure at 0-60 m and 0-200 ft of salt and fresh water in bar, atm and psi, how deep 10 bar and 20 bar are, and what that pressure does to a diver.
Read moreTraining & Certification10 min read
Scuba hand signals in one chart: OK, problem, up, low and out of air, gas pressure numbers, night light signals and surface signals, with agency differences.
Read moreTraining & Certification12 min read
What a divemaster can and cannot do, entry rules at PADI, SSI, NAUI and CMAS, listed course and yearly costs, how internships work and what the pay data shows.
Read moreTraining & Certification9 min read
A try dive asks for little swimming, but every Open Water course has a swim test. PADI, SSI, SDI, NAUI and CMAS rules compared, plus a plan for non-swimmers.
Read moreTraining & Certification9 min read
Maximum scuba depth by certification at PADI, SSI, NAUI, CMAS and BSAC, and why air diving stops near 40 m: narcosis, oxygen, gas use and no-stop time.
Read moreTraining & Certification6 min read
Most recreational dives last 30-60 minutes. Dive time at 10, 18 and 30 m, what ends a dive first (gas or the no-stop limit) and how long try dives last.
Read moreTraining & Certification10 min read
What a dive centre's agency logo does and does not guarantee, what ISO 24803 requires of operators, published supervision ratios and the questions to ask.
Read moreTraining & Certification11 min read
What changes after dark: primary and backup lights, torch signals, buddy distance, how the exit gets marked, night navigation and why air use goes up.
Read moreTraining & Certification10 min read
What makes a dive technical, entry rules at PADI, SSI, TDI, GUE and CMAS, the order to train in, the gear that changes, course prices and the risk data.
Read moreTraining & Certification7 min read
Rescue diver prerequisites at PADI, SSI, NAUI, CMAS and BSAC, what the course covers, how long it takes, the first aid and oxygen training needed and when to start.
Read moreTraining & Certification9 min read
Step-by-step DSMB deployment with a reel or spool: open vs closed buoys, inflation methods, how runaway ascents happen, colour conventions and practice drills.
Read moreTraining & Certification8 min read
How a drift dive works: negative entries, staying with the guide, reef hooks, which signals to carry, what to do if separated, and gas planning in current.
Read moreTraining & Certification7 min read
What the Advanced Open Water course involves at PADI, SSI, NAUI, CMAS and BSAC, what the card gets you on a boat, the fair criticisms and which dives to pick.
Read moreTraining & Certification8 min read
Certifications don't expire, but DAN suggests a refresher after one to two years out. What PADI ReActivate and SSI Scuba Skills Update cover, and what to check.
Read moreTraining & Certification1 min read
What to record in your dive log after every scuba dive: depth, bottom time, gas, conditions and buddy, when to write it up and paper versus digital logs.
Read moreTraining & Certification7 min read
Why divers bob up and down or swim head-up, how much lungs, BC gas, suit and cylinder shift you, and the hover and fin pivot drills that fix it.
Read moreTraining & Certification8 min read
Starting weights by wetsuit thickness, what salt water and aluminium cylinders add, and the end-of-dive weight check that gives you your real number.
Read moreTraining & Certification10 min read
Buddy check (BWRAF) checklist: what each letter means, what to check on your buddy's gear, the faults it catches, and how it compares with SEA BAG and ABC.
Read moreTraining & Certification9 min read
How to equalize your ears when diving: Valsalva, Toynbee, Frenzel, Lowry and tubal opening step by step, what to do if an ear won't clear, and barotrauma signs.
Read moreTraining & Certification10 min read
PADI and SSI are companies, CMAS is a federation of national bodies such as FFESSM. How ownership, course pricing, instructor rules and recognition differ.
Read moreTraining & Certification1 min read
Understand scuba certification levels across PADI, SSI, and CMAS: what each level allows, depth limits, and how the systems map to each other.
Read moreTraining & Certification8 min read
PADI and SSI set no upper age limit for scuba. What changes after 50: heart risk in DAN data, the medical checks that matter and realistic fitness targets.
Read moreTraining & Certification8 min read
Kids can try scuba in a pool at 8 and certify at 10 with PADI or SSI. Depth limits by age for PADI, SSI, CMAS and BSAC, plus medical and readiness advice.
Read moreTraining & Certification7 min read
What an Open Water course costs and what the price covers: agency eLearning fees, listed prices from dive centres in nine regions, extras and questions to ask.
Read moreTraining & Certification9 min read
Scuba diving vs snorkeling: training, depth, time underwater, cost and risk side by side, with try-dive rules from PADI and SSI and snorkel safety research.
Read moreTraining & Certification4 min read
Scuba began in 1943 with the Aqua-Lung: diving before it, how Cousteau and Gagnan built the regulator, Cousteau's life and how recreational diving grew.
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