Updated: Sep 11, 2020
BECOME A BETTER SCUBA DIVER
I'm a better diver because of "The Three B's": Buoyancy, Breathing and Body position. If you're huffing and puffing hard as you approach a creature, they'll get spooked. You have to learn to control your breathing so it's gentle, steady, and smooth as to not alarm the critters. You also have to have top buoyancy control to be able to get the subject in focus. Sometimes this means hanging upside down. You can't be up and down out of control while trying to snap, just doesn't work.
Body position is so important because you're so focused on what's in front of you, but you don't want to lose focus of what's behind you as well. You don't want to be one of those noobs kicking coral or stirring up the sand while trying to take a photo. When I'm really focused I try to keep my fins up, totally still and only using my ankles if I need to make any adjustments.
THINK LIKE MARINE LIFE
It sounds nuts, I know. The more in tune you are with the marine life, the better your photos will turn out. You'll start producing fewer fish butt photos and more elegant poses focused on the eyes. To accomplish this, you need many dives to get a feel for the way every species behaves. The Drum fish for example. They swim in redundant patterns, you want to learn to anticipate when they'll turn around and face you so you can snap that pretty face. You also start becoming more aware of what parts of the reef they like to hang in, what they feed on and symbiotic relationships if any.
SCUBA NERD CLUB
You're more enthusiastic about marine life so you're more likely to log your dives and spend countless hours flipping through the Fish ID books trying to identify and read up on that weird fish you photographed or that coral you never noticed before.
I have to admit that I hit a point in my dive career where I was feeling kinda bored because all I did was go on fun dives and wait for the DM to point at something. I wasn't really looking for myself. Everything changed when I started diving with a camera.
Don't worry, the SCUBA Nerd Club is a safe place. You don't have to deal with the Alpha know-it-all divers here.
A worthy mention is also being able to capture moments for your dive buddies. I've done everything from a birthday surprise to dolphin photobombs, couples kissing, and even whale sharks. People really appreciate having someone record underwater moments.