http://www.google.com/patents/EP0032223A1?cl=en
http://www.sciencedirect.com/science/article/pii/S0889974611001897
http://www.sciencedirect.com/science/article/pii/S088997461200182X
http://www.futuresfins.com/school-foils.php
Flat foiled fins break free sooner, and are better at controlling speed. Often surfers prefer them in fast powerful surf where they do not need to create additional speed
http://vimeo.com/34930514#
http://vimeo.com/23826127
http://www.youtube.com/watch?v=5fURpSJshPI
http://www.youtube.com/watch?v=ve_fyUfRUeA