The scoooba.com calculator takes the field data and returns the standardized result. What it computes, in order:
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Per-capture density. Each capture's count is divided by the area that capture saw, so the station's reading no longer depends on how much reef was in view. The division is done on the day's calibration scale, so two dives in different visibility compare like with like (Appendix A.3, A.7).
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The site index. The dive's reading for the hub is the average of the six capture densities — averaged, never pooled (Appendix A.3).
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The counting range. From the two observers' counts, the calculator reports the reconciled index with the spread between them, never as a bare number (Appendix A.5).
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The cross-dive comparison. Where a hub has more than one reading, the calculator compares them on the r/K-normalized scale, so two dives in different visibility are compared like with like (Appendix A.7).
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The noise floor. Where a hub has been re-occupied (Dives 3 and 4), the calculator reports the spread among the repeated readings — the variation the method produces on unchanged structure (Module 7).
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Optional — community structure. For demographers who choose to track the reef's structure as well as its abundance, the calculator also returns the diversity indices, the compositional turnover between visits, and the abundance growth rate. These are an advanced, optional layer (Appendix A.9) — not part of the core reading, which is complete with the density, its noise floor, and the limitations statement.