Start with high-confidence underwater photography books, then narrow by subgenre or adjacent topics.
I Am Maru
mugumogu
Chasing Shadows
Greg Skomal, Ret Talbot
Kraken
Wendy Williams
Secrets of the Whales
Brian Skerry, James Cameron
Secrets of the Octopus
Sy Montgomery, Warren K. Carlyle IV
The Soul of an Octopus
Sy Montgomery
The Great White Shark Handbook
Greg Skomal
The Shark Handbook: Third Edition
Greg Skomal, Gregory Skomal
