This handbook is your companion for the Reef Cartographer specialty. The course teaches you to do something that recreational diving rarely teaches: produce a measured, geometrically defensible map of a reef and the benthic environment around it. By the end of the course you will have collected acoustic bathymetric data with a castable consumer sonar, captured photogrammetric image sets of a reef feature, processed both into a single combined map, and stated the accuracy of your work — all without ever touching the reef.
The point of the work is not just a pretty model. A Reef Cartographer produces a documented, repeatable record of a reef's structure and condition: a baseline that can be re-surveyed months or years later to see what has changed. That makes you a contributor to reef awareness and citizen-science monitoring, not just a diver with a camera.
This is a technical specialty. The math is high-school trigonometry; nothing in this handbook requires anything beyond sine, cosine, and arctangent. But the course rewards preparation. The students who do well are the ones who arrive understanding what they are about to do and why. Read the modules. Work the examples. Do the self-checks. Show up ready.
Your final product is not just a pretty model. It is a small mapping package: raw bathymetric data, a cleaned bathymetric surface, a photo-derived product, registration notes, and an accuracy and limitations statement that tells another diver what the map can and cannot be used for.
There is also a companion website, reefcartographer.com, with free calculators for every formula in this handbook — footprint and grid spacing, refraction and field of view, baseline and shutter timing, orbit frame count, and an accuracy-statement builder. Run your own dive-plan numbers there before you get wet. You will see the relevant tool linked at each worked example.
Important: What This Handbook Is and Isn't
This handbook teaches reef-mapping skills that are added on top of your normal dive training. It does not replace your certified training, your certifying agency's standards, safe-diving practices, or your own judgment about the conditions in front of you. The checklists and procedures here are additions to your standard pre-dive safety routine, not the whole of it — many essential safety steps are assumed and not repeated. You and your team remain responsible for all standard safety procedures and for assessing conditions, whether or not a given step is printed here. Every depth, gas, and time number in this handbook is a starting point to be made more conservative whenever conditions or your own limits call for it. The maps you make are recreational and educational — not survey-grade or navigation-grade, and never to be used for navigation or safety-of-life decisions.
How to Use This Handbook
Five modules cover the academic content of the course. Each module ends with self-check questions; answers and rationales appear at the end of each module. The exam at the end of the course uses different questions; the self-checks are for your own learning.
After the modules, three knowledge articles go deeper on topics worth understanding in detail: why photogrammetry needs overlap, how registration actually works, and how a towed float behaves on the surface. These are not testable; they are for divers who want to understand rather than only do.
The Pre-Dive Calculation Worksheet appears once. Photocopy or print it three times — one for each open water dive. You will fill it out before each dive and your instructor will check it.
The References section at the end is a starting point for continued study after the course. Items are categorized by topic and ordered roughly from accessible to advanced.
What to Bring to Class
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This handbook, marked up however you find useful.
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A scientific calculator (phone calculator is fine if it has sin, cos, tan, and arctan).
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Standard recreational dive kit, properly serviced.
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Your Deeper Smart Sonar Max with the Fish Deeper app installed, paired to your phone or tablet, logged in, battery charged, storage available, and test-exported before the course day. During Dive 1 the device stays at the surface — with the Surface Data Operator (Config A) or sealed on the data buoy (Config B); you will not operate the app underwater.
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A finger spool with at least 30 m / 100 ft of line, pre-checked for knots and free-running.
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Your underwater camera or smartphone housing, with the intervalometer feature located and tested in advance.
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A surface marker float compatible with the Deeper Max (the course will not loan one; verify before the course day).
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Wet notes or a slate.
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A calibrated scale bar or known-distance reference for photogrammetry. Tip: a line pre-cut to your lane spacing (e.g. 5 ft) can serve double duty — as a scale reference in your photos and as a lateral-offset gauge at the Surveyor's Pivot. Use low-stretch line or (better) a marked rigid rod, note its true measured length, and manage it as an entanglement hazard — short, stowed, never trailing, cutter within reach.
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At least one accessible line-cutting device. The tow line is hand-held only; it is never clipped, tied, or wrapped to you.
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Any required local permits or site permissions for mapping protected, archaeological, sanctuary, or managed sites.