Reef Demographer · Learn
Learn it. For free. Whether or not you ever take the course.
The course's full knowledge development — 24 lessons, about 78 minutes of reading — with a quick check after each so you know whether it landed. No account, no sign-up, nothing to buy to read it.
Anyone can learn this. Only an instructor can certify you. Everything here is open — read
it because you are taking the course, because you are curious how a reef gets counted, or because
you want to run the method yourself. Nothing on this page is graded, recorded, or sent anywhere,
and there is no wrong answer that costs you anything.
What a certification card attests is not that someone read something. It is that an instructor watched them do the work in water and judged them competent. That part cannot happen on a website. Taking the specialty itself means instruction, in-water time and PADI's certification fee, arranged through a dive center in the ordinary way — the reading is free, the card is not.
What a certification card attests is not that someone read something. It is that an instructor watched them do the work in water and judged them competent. That part cannot happen on a website. Taking the specialty itself means instruction, in-water time and PADI's certification fee, arranged through a dive center in the ordinary way — the reading is free, the card is not.
Not started.
Progress is stored in this browser only — not on a server, not in an account. Switch device or clear your browser data and it starts over. Nothing about you is collected.
- 01 Section Two: Knowledge Development 1 min
- 02 Module 1 — The Method: What a Reef Demographer Does 4 min
- 03 Module 2 — Visibility and the Detection Radius 5 min
- 04 Module 3 — The Camera and the Capture 5 min
- 05 Module 4 — The Survey Pattern 5 min
- 06 Module 5 — Counting and Species Identification 4 min
- 07 Module 6 — Team Operations and Human Factors 4 min
- 08 Module 7 — The Index, the Noise Floor, and Limitations 4 min
- 09 Module 8 — Going Further: Community Structure (Optional) 1 min
- 10 Module 9 — AI-Assisted Counting: the Machine Proposes, You Decide 3 min
- 11 Section Three: Open Water Training Execution 1 min
- 12 Skill Session 1 — Survey Dive Planning (Dry, Reviewed Gate) 9 min
- 13 Dive 1 — Calibration and Practice Run (No Camera) 6 min
- 14 Dive 2 — The Survey Ring (First Hexagon) 4 min
- 15 Dive 3 — Re-occupation and the Noise Floor 6 min
- 16 Dive 4 — Independent Capstone Survey 3 min
- 17 Dive 5 — Half-Radius Diagnostic Check (Optional) 4 min
- 18 Certification Performance Checklist 1 min
- 19 Section Four: Analysis and the Limitations Statement 1 min
- 20 What the Demographer Brings to the Analysis 1 min
- 21 What the Calculator Computes 1 min
- 22 The Noise Floor and the Reading Rule 1 min
- 23 The Limitations Statement 3 min
- 24 The Data Package 1 min
Want the card? The in-water work — calibration, the six-station ring, a re-occupation that
gives you your noise floor, and a capstone survey you run yourself — is what earns the
certification. If you have worked through these lessons and want to do it properly,
get in touch.
Generated from the Reef Demographer Course Guide, version 1.0 — its knowledge development modules, open water dives, and analysis section. The course documents are the authority; if these pages and they ever disagree, the documents are right.