Dive sites familiar during the day, transform into dark wonderlands of sparkling bio-luminescent organisms on night dives.
They only come out after dark. This not only true of vampires (Roatan is certified vampire free for 2020), but also of many reef creatures. Animals normally tucked away in cracks and crevices in daytime, are out foraging and socializing at night. For instance, King Crabs, Lobsters, and the elusive octopus can be rare finds in the daytime, but are commonly seen out and about on the reef at night.