Lots of people discuss fins on the Internet.
This one's good, these have turbo ridges, this one is faster because its red.
Which fin is best?
There is no one BEST fin, but there are categories.
Which I will, unfortunately over simplify.
Short and wide like these
Or long like these
The short ones are generally easier to kick with but produce less total forward propulsion due to a smaller surface area.
The long ones have a larger surface area and you get more forward propulsion but they have also been described as strapping 2 by 4's to your feet.
Which one is best depends on several things the most important of which is you.
First the fins you use MUST fit YOUR FOOT and be comfortable or at least tolerable.
If you have wide feet you need fins with a wide foot box. Vipers, while not very wide have a model that includes neoprene lining. A very good idea and one that can be used to customize any fin.
Some break in of your feet is to be expected.
Second you need to look in the mirror at your legs.
If you see tree trunks growing out of your body you can use long powerful leg movements and long fins to rocket thru the water.
If you see wispy thin legs try the wide short fins. You can use the short fast kicks to provide bursts of speed to rocket you thru the water.
So try all your friends fins and find some that are comfortable.
Hint if you wear Duck Feet upside down you get another half size up.
I am not sure why but I think it has to do with some sort of fin magic.
Hint number two there are those that will take a big fin (see the UDT's above) and carve them up to fit them better and change the flex characteristics. Thinning the blades increase their flex. Carve the straps to accommodate your ankle bones. Go nuts with it. It will do you good. See Swaylocks or Surfmatz for several discussion about fin mods.
Here are some Duck Feet that have had the blades shortened and thinned out.
These are commercially available so you don't get rubber bits all over the garden.
So even if you are not of the mat or boogie board persuasion get a pair of fins for the summer. Body surfing is a blast and it one of the things surfers lost touch with when "Leashes Ruined Surfing"
Let me know what kinds of fins you use.
I am starting a personal collection and hope to, one day, be the Imelda Marcos of swim fins...
Personally I use a several pairs of Duck Feet (no not all at the same time) but a smaller pair during the summer when I wear them over fin socks and a larger pair during the winter that fit nicely over my booties.
I am looking at Da Fin as an interesting mid-sized fin