So often in our haste to take pictures underwater we forget an important fact: to be a good underwater photographer, you first have to be a good diver. The good news, however, is that being an aspiring photographer doesn't have to interfere with your development as a competent diver. In fact, it often accelerates it.
Many of the skills we develop in life are born out of necessity. Likewise, mastery of fin pivots, for example, may come out of the need to get in close to a photo subject rather than rote repetition. The ability to hover effortlessly may arise out of shooting stingrays and not advanced certifications.
The line is drawn where photography interferes with your ability to be a safe diver. It is your responsibility to consider the factors leading to a dive. If you don't think you will be able to take pictures without harming the environment or doing so safely (including your responsibilities to your buddy), it is on you to make the call and leave the camera behind.
Usually this is not the case. Enjoy learning how to take photos underwater, and appreciate the side benefits it has on your abilities as a scuba diver. You may surprise yourself at just how competent a diver you become in the process.
Photo by PhotopediaPhotos