Try Anthony Appleyard's free stuff. He has a large selection of scuba / water related items.  There are a few different fins, one is posable.

http://www.renderosity.com/mod/freestuff/index.php?user_id=659

And there is a whole lot more at his website too.

http://www.buckrogers.demon.co.uk/3d/3d.htm

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi