Dataset: Vertical temperature data from Little Cayman, Cayman Islands, during the 4th global bleaching event from September 2023 (Molecular and Morphological Coral Adaptation project)

These data were collected from Little Cayman Island at three specific sites: Randy’s Gazebo (19.683783, -80.082967), Marylin’s Cut (19.684733, -80.079067), and Mixing Bowl (19.684920, -80.078000). Each site features a near-vertical wall that begins at approximately 10 m and extends to depths exceeding 1,000 m.

At each site, a single transect was secured to the substrate at the shallowest point of the vertical wall and extended downward to a maximum depth of 50 m. Seawater temperature was recorded throughout each dive using HOBO ProV temperature loggers attached to the backs of two divers. Depth-specific temperature readings were determined by correlating logger timestamps with depth data from each diver’s handheld computer (Shearwater Petrel). All dives were conducted using closed-circuit rebreathers (Hollis Prism 2).