Slow and steady pace. It's a marathon not a sprint.
And they say there's no such thing as a stupid question.
I don't want to crayon in a joining thread but I feel obliged to point out the absurdity of a wannabe diver being worried about swimming.
Did it not occur to the OP that swimming might be an integral part of being a diver?
I'm going to buy some fins, ideally wouldn't want to spend an excessive amount but also want some that will replicate the ones used by navy divers! Anyone got an info????
The ones Pusser use are called Jetfins and the techie scuba divers use them too as they are black! They are hideously expensive. Just get a normal set of fins (if you feel you must) from Decathlon, at least you'l be using the ame muscles.