Congrats on the trip and the new camera for diving photos. Your photos remind me of mine in several ways. Upon looking at the work shown via members here and reading on underwater diving, here are some thoughts. I have been critiqueing some of my pics and the thoughts are similar.
First, immediately get The Unerwater Photographer, 3rd ed. by Martin Edge. I learned more in 1 hour with it than with 10 yrs of trying to figure it out by myself. Seriously!
After reading it and looking your photos and mine, here are thoughts I take from it and project to your shots.
Consider what these would have looked like if you could have been lower and closer.
Take the 4th pic for example. What if you had been close enough that all you saw was the anemone and the fish and you were below it shooting up, or at least level with it. The 3 dimensional depth and interest might have been higher.
Same with pic 2. Consider if you had been level with him and close enough to see the eye sharply with inner mouth details. The whole fish would not have been in the pic but the pic might have been more impressive and dramatic. I think the angle with the fish leading to the upper left works well.
Consider an eye to eye pic with the nudi or at least horizontal relative to him with the high depth of field with your lens on wide angle and high f-stop and what that might look like.
What would the ray pic have been like if you had been laying on the bottom, on the left side from the shot taken... and with half the distance. Not saying the ray would have accepted that from you but imagining what that would be like, having the tail leading to the upper left of the pic again.
Does that any of that make any sense? I am just a beginner to this as well and the others will likely have far better insight.
The more I read and study, the more I seem to be thinking.. get below and shoot up and get closer than you think possible and once there, try to get closer.
Yours are attractive snapshots of a great vacation and great for memories of what you saw and looks like having a good time.