Dive fins may look simple, but the fact is that, a lot of research and science goes into their designing. Manufactures will often combine different material and blade designs to ensure that the correct energy is transferred from the leg to the fin with each kick cycle. We already reviewed the best scuba fins available to buy here and it is worthwhile if you can take a quick moment to read up on it.
There are many styles and types to choose from, and that is why, it can sometimes be difficult to choose the right pair of fins.
Types of Scuba Fins
There are two basic styles of scuba fins – Full Foot Fins and Open Heal Fins. What fin you choose can depend on where you are diving.
Full Foot Fins
These fins have closed heals and are usually worn bare foot or with thin neoprene fin sock for added comfort. They are usually used for diving in worm tropical waters or snorkeling on the surface, as you cannot use them while wearing booties. These fins are also usually lighter. The price is less than Open Heal fins. Most Full Foot fins are usually very flexible, as there is less mass.
Open Heel Adjustable Fins
Scuba diving fins that you will usually see are the Adjustable Open Heal fins. To use them, you must wear neoprene boots (dive boots). They are good for diving in colder waters. They are designed with an open foot pocket. There is an adjustable heel strap to keep your foot secure in the pocket. These fins are usually stiffer, and are made from stronger materials. Remember, always buy your booties first, before going for these fins. That’s because, thickness of your booties will decide the size and fit of your fins.
Full Foot Fins vs. Open Heel Fins
Full Foot fins are usually cheaper than Open Heal fins, are easier to wear and less bulky, but if they are not a perfect fit for you, then they will cause lots of friction and blisters. When you are selecting Full Foot fins, always go for fit.
The downside of these fins is that, in cold water, they don’t offer any thermal protection for your feet. Also, you must consider where to walk on the shore, as without boots, your foot is vulnerable over rock.
Because of these restrictions, most divers select an Open Heal fin. They are more adjustable, comfortable and versatile, and also provide cushioning and chafing protection. However, they are more expensive and bulkier, and may also have complex strap adjustment mechanisms. You will get thermal protection in colder water if you wear the find with your dive boot.
Versatility is a key with an Open Heel fin. You can wear the same fin with a pre-fitted dry suit boot or a pair of trainers, so, you don’t need to have different fins for different conditions. Plus, Open Heel fins also provide more stability and maximum propulsion. That is another advantage.
In terms of fit, Open Heel fins need to feel as though they are holding the boot and the foot in the foot pocket. The foot should not feel as though you can wiggle it easily from side to side. Also, not too much of your boot should stick out of the bottom of the foot pocket. Fit will vary between style and manufacturer, but most manufacturers will provide a shoe size range as a guide for each fin size to make fitting a little easier.
These days fin blades are relatively larger and more efficient than before. Many technologies and materials are used to increase performance and cut the effort needed to move your body through the water.
Here are some of the blade types you will find.
Standard Fins (Paddle Fins)
This blade is flat, and so water will spill over the sides of the fins. They can sometimes be unstable. These are the simplest in design and generally have a flat blade surface. They work much like an ore, propelling your forward with every kick cycle. Some manufactures put ribs on each side of the blade to provide more strength, and to contain water inside the blade, thus increasing propulsion, efficiency, and stability.
These are a bit better. They are paddle fins that are vented at the base of the foot pocket. The vents allow water to pass through the fin during the recovery stroke of the kick cycle, and prevent water from passing during the power stroke. This reduces efforts during the recovery stroke, and increases kick efficiency. A few vented fins are designed to stream water over the length of the fins blade, which in turn increase propulsion.
These fins use different types of materials in the blade allowing it to flex along the width of the blade. When you kick, the fin forms a “U” shape channel that captures and contains the water more efficiently than just having ribs on the side of the fins. This channel creates a focus “Jet” of water greatly increasing propulsion.
There is a split running down the middle of the blade with stiffer sidewalls for support. Most fins use recoil to give thrust by pushing water backwards. But these fins work much like the wings of a plane or boat propellers. You are propelled through the water by the lift created by water passing through the splits in the fins. And so, kicking the fins is very easy. It reduces the load on your ankles and leg. A concern with these types of fins is that they can sometimes be hard to maneuver in tight areas, and are not good with the frog kick.
This is a new type. They have a point on the blade that hinges. The hinge in the blade lets it work efficiently with the power stroke. This technology is used in many ways. Some manufactures use bungee bands, narrow sections in the blade and flexing bars, as well as standard or channel blade to create a more efficient pair of fins.
I hope I have been able to cover most of your questions but if you have any doubts on choosing your next fins please drop me a question in the comments below and I will be sure to get back to you. I am also interested to know if there is anything you feel I could have added more to the post above.