When I'm trying to take photos and I'm up after 35 minutes, but everyone comes back up after an hour telling me about the turtles and sharks and whatever they saw, but I didn't, SAC/RMV become a proxy for enjoyment. Not to mention that, as a physician, that physiologic data is too tempting to ignore
.
That much differential is not your fins.
And yes, the sharks and turtles do know to wait so that only the last few in get to see them
. Or, they are FOS and just pulling your leg. The longer you are in the water, the more you will see, but fins are not your problem though it could be a minor contributor.
You mentioned a camera, is that new to your kit? Just wondering. Being comfortable in the water is going to be the biggest part and good cardiovascular fitness never hurts. And trim, of course that is a big factor. There is also a powerful mental component and if you think, be true or not, that your fins are an impediment, get some new ones. The two best fins I have encountered of the last decade are the Scubapro Go-Sport and the Deep Six Eddy Flipper but neither are magic. And right in there, though longer, are the Mares Avanti Ouattro. Mind over matter, that may be where you are.
Make sure your camera rig is neutral and chill out.
If I hand off my camera rig to my wife she gets all out of wack, and it is like 2 ounces negative, it is mental with her. And she is absolutely the world's worst photographer, she could not be worse if she tried to be worse, that bad!