Photo: (c) Dan Schofield, some rights reserved (CC BY), via Wikimedia Commons, CC BY 4.01. Twins
Koh TaoSeen on 22% of dives in September
Marine life
Cheilinus chlorourus
Best monthly chance of seeing it per dive, at the best site in each destination.
Chances are the share of dives on which it was seen, in the best month.
Photo: (c) Dan Schofield, some rights reserved (CC BY), via Wikimedia Commons, CC BY 4.0Seen on 22% of dives in September
Photo: (c) portioid, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 21% of dives in September
Photo: (c) ig: underwater.logs, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 19% of dives in September
Seen here: Moon wrassePhoto: Leonard Low from Australia, via Wikimedia Commons, CC BY 2.0 · not taken at this siteSeen on 18% of dives in September
Photo: (c) Jan Ebr & Ivana Ebrová, some rights reserved (CC BY), via Wikimedia Commons, CC BY 4.0Seen on 18% of dives in October
Photo: Amada44, via Wikimedia Commons, CC BY SA 3.0Seen on 17% of dives in September
Photo: (c) portioid, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 15% of dives in July
Photo: (c) Jean Jacques Godon, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 15% of dives in November
Photo: (c) portioid, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 15% of dives in September
Photo: (c) Jan Ebr & Ivana Ebrová, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 14% of dives in November
Photo: (c) portioid, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 14% of dives in July
Photo: (c) Kat Lim, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 14% of dives in October
Photo: (c) portioid, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 13% of dives in September
Photo: (c) luluchouette, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 12% of dives in July
Seen here: Doublebar RabbitfishPhoto: H. Schlegel, via Wikimedia Commons, PD · not taken at this siteSeen on 9% of dives in June
Photo: (c) portioid, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 8% of dives in July
Photo: (c) portioid, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 7% of dives in July
Photo: (c) Shane Austin, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 6% of dives in July
Photo: (c) portioid, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 6% of dives in July
Photo: (c) Gonzalo Ganda Álvarez, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 4% of dives in October
Photo: (c) portioid, some rights reserved (CC BY), via iNaturalist, CC BYSeen on 2% of dives in July
The ocean covers 70% of the planet but is the least-recorded place on Earth. Scientists can't be on every reef. Divers are.

Most ocean records come from a few coasts. Log every dive, even quiet sites.
Full dive logs show when a species goes missing. Log every animal, not just the highlights.
Change only shows up over years. Keep logging your home reef.
Lookalike species trip up records. Tag animals and add a photo.