Night dives are not as dark as you would expect
Most start at dusk and everyone has at least two lights. If anything try not to blind the fish. Circle them and try not to make them a target.
If anything interesting shows up everyone has a light on it so nothing is going to sneak up on you.
Some marine life like shrimp are drawn to the light so on a few dives we’ve been hit with little shrimp
On all my dives the only thing that ever made my heart stop was on a Jersey dive with limited viz having a big Wolf Ell come to my light
Bald divers need to wear a beanie because you won’t see jellyfish :(