One of the best answers to this question for me came in the form of a videotape. I went diving, several years ago, with someone I had just met who had come up from Southern California. We went on a dive in the Edmonds Underwater Park, which is a silty plain which has been "seeded" with things to create animal habitat -- small pleasure boats, concrete pipes, a pipe "slinky", and other and very varied items. After a short time, they all get covered with various form of life, ranging from Vancouver tube worms to long-finned sculpins, a wide variety of nudibranchs, a spectrum of rockfish, and some of the largest ling cod and cabezons you will see in the Sound.
We spent over an hour touring, and I admired schools of tubesnouts and shiner perch glistening in the sun, and spotted hooded nudis in the eelgrass.
Nick made a video. When he put it up a week or so later, I watched it in consternation. Where were the fish? Where were the nudibranchs? On the other hand, I realized one of the structures we had swum over was a BOAT, complete with its steering wheel intact . . . which I hadn't even noticed when we were there. Nick had swum with me almost kick for kick, but had had a completely different dive experience, as he looked at the structures themselves and not what lived on them. We both had a ton of fun, and at the same time, but the fun was completely different.
I watch the videos of my friends doing technical dives on wrecks, and see them scootering fast and doing rolls and loops, and I wonder why they make the effort and buy the helium to go down and do aquabatics they could do shallower. The answer is that we all dive for different reasons and derive different enjoyment from doing it.
I took a critter ID class; it massively improved the quality of my dive time in Puget Sound. But I LOOK at all the little live things . . .
