Recently, I taught a workshop for an experienced dive instructor who wanted to learn to take better pictures. The day before the scheduled dive, we met for a dive briefing and I explained the buoyancy skills we would do.
The first task was to establish neutral buoyancy 4-5 feet off the bottom and stay there for 90 seconds. This is not that hard to do especially when holding the camera and not looking through it. The second skill is to maintain a horizontal position while looking through the camera as if photographing a subject and maintain neutral buoyancy two feet off the bottom for 2 minutes.
Mastering buoyancy is the most important skill to master. When creating fish portraits, a photographer might need to be in the same position for a long time. While the diver has their eye to the camera to catch the moment they have to consciously avoid silting up the bottom, or touching the reef with equipment or body. This skill also emphasizes the importance of breathing in a rhythm and never holding your breath.
The third skill is to establish neutral buoyancy about 6 six feet off the bottom and change camera settings and strobe power settings. Some divers have a tendency to kick a lot while they change settings and this causes coral to get broken, the visibility to get stirred up, marine life to get scared and disappear, and sometimes for divers to ascend too fast. This skill teaches divers how to make changes safely and smoothly.
Mastering ones buoyancy will help make sure that when the moment comes, a diver need only depress the Shutter.