Types of Fins
There are many different types of fins available. Let’s look at the main ones found in conventional snorkel sets.
Open Heel Fins
These are the type most likely to come in a snorkeling set you buy. The reason is that the open back design allows for a greater variety of foot shapes and sizes to be accommodated by the fin. The open back design relatively easy and quick to put on. Many open backed fins have a quick release on the strap that allows for even greater speed when donning. One drawback to the open heel design is of course the exposed heel. This makes walking on sharp rocky surfaces or rocky sand somewhat painful. It is possible to wear thin booties inside the fin to avoid this problem.
Full Foot Fins
These types of fins fit around your whole foot like a shoe. The advantage to this design is a more secure fit that reduces drag considerably over an open-heel fin. The inside surface of the full foot fins is usually non slip and can be worn barefoot, but diving or aqua socks, or thin booties are recommended for best performance. Another issue is ensuring proper fit, as there is much less or often no adjustability with a full foot fin. One trick is to adjust the thickness of your sock or bootie as needed to compensate for a fin that is too tight or loose.
Now what about split fins or paddle fins?
Split fins as the name implies are split, usually in the middle. This has the effect of lessening the rigidity of the fin which helps reduce resistance against one’s leg muscles in the water. Basically the fin has more “give” which in many cases will help those who are weaker swimmers or have difficulty with changing direction or treading water while wearing fins. It would also be more appropriate people who may suffer from chronic leg, foot, or ankle problems. Split fins are also a little more appropriate for surface cruising.
Paddle or blade fins are smooth and have an unbroken, flat shape across their surface. They are rigid and this aids in transferring maximum energy from leg muscles to propulsion in the water. Because of this, they generally cause more fatigue than split fins. For those experienced with using fins, paddle fins provide more maneuverability and control especially at low speeds.
Paddle fins should technically yield more speed for those who want it, but for the casual snorkeler there is little practical difference between the split or paddle designs, and usually paddle fins are included with snorkel sets. Keep fin types in mind when shopping for and comparing snorkeling sets.