Trux, I appreciate your comment. Problem is that very few videos of competitors adequately show turns. Try finding a video of Natalia, for example, that adequately shows her current turns. Videos from the surface are often blocked during the turns by judges, glare (see Katarina's video below), and safety personnel, and underwater videos are mainly at the center of the pool, far away from the turn action. There are plenty of push-off turns available for viewing since a lot of folks do them, but if you want another kind of turn, it takes a lot of searching.
In any case, I include here several good videos of the various kinds of turns -
Outside turns (face is toward the wall during the turn)
I do not know who this is but it is a good demonstration.
Melanie Long
KATARINA TURČINOVIĆ just explodes out of her turns.
Inside turns (face is toward the pool during the turn)
Natalia Molchanova
I cannot find a good video of her doing this kind of turn using a hyperfin.
Push-off turns
Eric Van Riet Pap
Alexey Molchanov
Side-spin or Single-axis turns. This is a turn mainly for rigid fins such the DOL-Fin, and Lunocet (though I have not tried it with the Lunocet). Many people do this turn, or a variation if it, using their monofins with poor results.
Ron Smith
Flip Turns
There used to be a video of Wes Lapp up on vimeo doing flip turns. Is gone now though. Not sure why.