Many divers that are not into photography simply swim continuously through their environment expecting that this will give them then best chance to see everything there is to see. For things that do not swim away this makes perfect sense.

If on the other hand you really want to see fish behaviour, the opposite is true. Pick a spot, really any spot will do, settle down, relax and wait.

It will not take long, perhaps a couple of minutes or two, but the fish will come to you. On this dive I had three curious blennies come and play with me for as long as I was prepared stick around.