Comments about Aqua Sphere Microfin HP Fins:

SUPER FOR EXERCISE, NOT SCUBA, BUT 13 Wide SIZING IS DIFFICULT

I used a pair of Aqua Sphere microfins, now discontinued, in my exercise pool for 2 years and loved them. I liked them so well I tried them SCUBA diving in Costa Rica but while they were adequate for level swimming, they were too small on the surface or if I really wanted to go over and look at something. When I lost one coming out of the ocean, I went looking for a replacement. I am 68 years old, with 13 wide feet that are a hard thing to fit. I ordered, on the theory that all it would cost would be some return postage:
NGRFSHXL Sea Horse Fins XL (the box is labeled National Geographic "Snorkeler")
ASRFMH12 AquaSphere Microfin HP 11/12
HEDSFE11 Head Swin Energy Fins 11-12

The Sea Horse Fins fit the best, largely because they have a BIG TOE BOX that doesn't crimp your toes when a "top of the size range" foot is wedged into them. They are also the cheapest, and the design has a piece of plastic integrated into the plastic which makes them easier than "all rubber" fins to pull on. They work great. The others are ok, but feel much tighter at the toes on my feet.