Coral Cover: BVI Necker 2026 (snorkels)

Shaded value = in the CV mean (shade deepens with cover) Gray italic = shown for comparison but left out of the CV mean: the gold standard (the reference value) and the manually annotated in CoralNet CoralNet benchmark annotations (reference values, not models), Coralscapes (not trusted), and any value that reuses the reference's own data n = frames behind the value — = not run or not applicable (see each region's notes) Site names and method names link out (new tab)

Coral Cover: BVI Necker 2026 (snorkels)

4 sites · 324 photos

Gold standard = 35 manually scored (via CoralNet) photos from Red Dock.

Site	Date	Headline (site page)	Claude	Gold standard	DINOv3	CoralSCOP	Mean ± SD of CV	Range
Red Dock	2026-07-01	7.4%manual, area	8.0^dn=87	6.3^en=35	20^bn=93	21^cn=93	16 ± 7.2	8.0–21
Turtle Beach	2026-07-01–02	3.1%Claude, area	3.1^dn=83	—^a	17^bn=91	17^cn=91	12 ± 7.9	3.1–17
Bali Hai to Turtle Beach	2026-07-02	2.5%Claude, area	2.5^dn=89	—^a	14^bn=89	12^cn=89	9.5 ± 6.1	2.5–14
Watersport Beach to Bali Hai	2026-07-02	2.4%Claude, area	2.4^dn=51	—^a	11^bn=51	12^cn=51	8.7 ± 5.5	2.4–12
All sites (unweighted mean)		4.0%Claude, island	4.0	—	16	16	12 ± 6.7	4.0–16

Notes for BVI Necker 2026 (snorkels) (9)

[a] No hand-labeled frame at this area.
[b] DINOv3 (in-house, frozen Alor/Indonesia model) = mean hard-coral probability over 20 synthesized points per photo, NO water/fish class, so not a benthic denominator (from the map's site cover table).
[c] CoralSCOP = per-frame sum of colony-mask area fractions (zero-filled; overlapping masks double-count), averaged over frames with an ok row. Area index, not a point count: denominator differs from any point-count reference. It is also unstable frame to frame (the same subject has scored 94.1% in one photo and 23.3% in another), and the mask sum overstates cover most on the healthiest reefs.
[d] Claude = blind HC/NOT/UNK calls on the unedited frames, 30 CoralNet points per frame, cover = HC/30 (all-30: WATER/FISH are unknown outside the reference frames), mean of per-frame cover - the arm's own convention (the arm's results notes). 310/310 frames.
[e] Gold = the author's own CoralNet labels on the 35 Red Dock frames in which he labeled all 30 points, on the all-30 denominator used for Claude here. With water and fish points left out of the denominator, the same frames read 7.4%, the value quoted on the Red Dock page.
Mean/Range: Mean ± SD and Range are over the CV cells that enter the mean (CoralNet where independent, DINOv3, CoralSCOP unedited/edited, Claude). Gold standard, frames manually annotated in CoralNet, Coralscapes and same-measurement cells are shown in gray italic but never averaged.
Headline (site page): the coral-cover figure the site's page, report card and map pop-up print, with its method; it is never averaged into the CV mean.
Methods: Claude (Anthropic); DINOv3 (Meta; paper; used here as the frozen backbone of the in-house classifier); Coralscapes v1 and v2 (EPFL-ECEO; dataset paper, code); CoralSCOP (Zheng et al., CVPR 2024); CoralNet.
Sites: names drop the region prefix (hover for the full name) and link to the site's CRD page, or to the regional summary page where the site has none. Date = survey date from the map pins (first–last visit); sites are listed earliest first, undated sites last.

All regions