A frame is not a measurement until somebody has scored it. That happens topside, on a screen, and it is a different skill from taking the picture. It takes about ten minutes.
Points, not outlines. The obvious way to measure how much of a frame is coral would be to trace every colony and add up the areas. Nobody does it, because tracing an outline is a judgment about where a boundary lies, made hundreds of times per frame, and boundaries on a reef are genuinely ambiguous. Where does live tissue end and turf begin? Those judgments do not cancel. A scorer who draws generously produces systematically higher cover, every frame, forever.
Point intercept replaces the judgment with a sample. Fifty points are scattered across the frame at random and you answer one question at each: what is directly underneath this one? The answer is a category, not a boundary. Sixteen points on hard coral out of fifty is your estimate of hard coral cover: 32 %.
Fifty points per frame is the recommendation, 25 the minimum, and you record how many you used. Both are within the range the established monitoring programs use, and staying in that range is part of what lets your Entry sit alongside their data instead of alone. Fifty costs twice the clicking of 25 and buys a third less sampling error — and, more importantly, a smaller floor, which is what you will want on the day you come back.
The class list is not yours. You score into the benthic classes in general use — hard coral, soft coral, dead coral, macroalgae, coralline algae, turf, other invertebrates, and non-living substrate split into sand, rubble and rock. You could invent a better list for your reef. It would describe your site more finely and be worth less, because nothing could be compared with it. Most of the value of a monitoring record is the value of the corpus it joins.
Bleached coral is coral. A point on bleached tissue is scored hard coral. There is no bleached class. If there were, a bleaching event would show in your record as a fall in coral cover, which is false — bleached coral is still coral, still there, and may recover.
Indeterminate is an answer. Bleached tissue is white; recently dead skeleton is also white; they mean opposite things and in a photograph they can look identical. The cue is texture — living tissue softens the fine structure of the skeleton, bare skeleton shows it sharply, and dead skeleton goes green-brown with turf within weeks. When the frame cannot support the call, score the point indeterminate. Never assign it to whichever seems likelier. Run the governing test: if you guessed, a worse frame would produce a more confident count in whichever direction you lean. Saying I could not tell is the direction that fails safe.
Your buddy scores your frame too. Same frame, same points, no conferring. Both numbers go in the Entry side by side. Where you disagree, that is real information about how well the frame supports the call, and it is reported rather than averaged away. And the positions of the points go in the archive — a point list or an annotated frame — so that anyone, later, can score the same spots again.
A machine may propose; you decide. Software can label every point in a frame and turn ten minutes into two. The confirmed classification is the score of record, the raw model output is logged and never reported, and the model version is written down. Models change silently between versions — if the raw output were the record, a software update between two visits would appear in your data as change at the reef. That is a faded reference chart, in software.