Slab said..
You swapped for a dolphin fin?
Yes.. I love fins.. and I'm still a HUGE fan of the plane old dolphin fin shape.. btw.. The stock fin is great and there's no real need to change it..
One thing that I do like about the swept back dolphin fin over the stock fin is the dolphin fin can be dragged across the sand in shallow water better than most other fins that tend to catch.. or dig in and grab causing the board to suddenly stop sending you over the nose..

The new shape stock Naish fin is very nice and the more upright shape helps with both turning and stability.. and the little extra rake on the new fin helps with tracking and not catching weed..
It was pretty shallow in some places where I paddled that day and the swept back dolphin fin works well there.