Here's another dolphin family (or pod) with father, mother, and two kids, one slightly older (larger) than the other. I laid on the sandy bottom waiting for this sort of thing to swim over me. You cannot easily control them, you just have to be patient and wait until they swim into your viewfinder. One of the hardest things to do is keep them there - many pictures are bad because a beak or tail is cut off due to the fact that these creatures never stop swimming, and they move pretty fast much of the time......patience is important!