Scuba Diving Fins FAQ

1.  What type of scuba fins are there?

There are a vast range of different scuba fins available.  Though, generally, all fins fit into one of two categories. Open heel fins, where the heel is left open and an adjustable strap is used to hold the booted foot in the fin. Or, closed heel fins that have a foot shaped pocket where either a bare foot or one wearing a thin wetsuit sock is inserted. For scuba diving, most industry professionals would advocate the use of the open heel style of fin, the fact that a wetsuit boot is worn with these fins provides the diver both with comfort and safety for the foot whilst not actually wearing the fin itself.  Along with the basic categorisation of either Open Heel fins or Closed Heels fin, there are various differences in the blade style and construction of fins, these include:

• Chanel Fins – These fins are constructed using both hard plastics and soft flexible rubber. The rubber sections of these fins usually run in gussets, lengthways down the fin blade, from the end of the toe pocket to the end of the fins. This allows the fins whilst being kicked by the foot, to bow widthways across the blade, creating a U shaped “channel” which pushed more water down the fin blade than traditional paddle fins.
• Traditional Paddle Fin – these fins have either a full foot or heel strap.  They work by moving water up and down as you kick and are useful for free diving or diving in currents as they can propel you forward very effectively.
• Pivotal Blade Fins – many modern fins have a special pivoting blade which will angle itself as you kick to optimize the efficiency of the fin.   These can be tricky to get the hang of at first as the angled blades can sometimes move into the wrong positions causing you to lose kick force.
• Split Blade Fins – split blade fins are also known as ‘Bio-Fins’. These fins have blades that are divided into two parts.  They can increase the efficiency and power of each stroke and are supposed to minimise the number of kicks you need to make to cover a set distance. Some divers find split fins difficult to use and other swear by them. They are best suited to a smaller, quicker kicking action, often referred to as a “flutter kick”. Large strong traditional “scissor kicks” are not as effective with this style of fins.
• Force Fins – these fins are a lot smaller than other fins on the market and are designed to mimic a whale’s tail (on a much smaller scale of course).  Many divers find these small fins have superior kick efficiency but it can take a while to get used to them.

2. Do I need stiff or flexible fins?

If you have a strong kick then you will find the stiffer blades provide an effective fin that will propel you quickly through the water.  However if you do not have such a strong kick then the stiffer fins can be very tiring.  You will find a softer, more flexible fin much easier to use and more effective. 

3.  How do I choose the right scuba fins?

Comfort is very important when it comes to choosing fins.  There is no set way of working out which fin is right for you. In the beginning it is best start off with a either a channel fin or traditional paddle fin and see how you get on.  These standard fin designs are easy to use and suit a wide range of different divers.  There are also a number of paddle type fins available in all different shapes and sizes so you should be able to find something that suits you.  Another important factor when choosing fins is your budget.  Traditional paddle fins can be good value for money and there are many cost effective options.  Once you have got more experienced at diving you may want to try out a few different fin types such as split fins and force fins to see if another style would suit you better.

4. How do split fins work?

Split fins work by pushing water back, rather than moving it up and down like traditional paddle fins.  They use turbulence in the water to provide thrust. As the split fin is kicked, the two halves of the split part, producing a curved “V” formation in the middle, similar to the fluke of a whale’s tail. This wide split creates a swirling, spiral vortex of water, which draws water down the face of the blade, propelling it past the tips of the blade and out the back. Given the physical fact that all actions have equal and opposite re-actions, the effect of the water being drawn down the fin is that the fin is pushed equally in the opposite direction, providing forward motion.

5.  What fins are best for high performance diving?

You will need to spend a bit more money on fins if you want high performance designs.  Top range fins are made from superior materials and have advanced features.  A high quality fin can provide much more effective and efficient propulsion and top brand names such as Mares and Cressi can provide some affordable options.

6.  Why do I need fins when diving?

Fins increase the effectiveness of your kick stroke when you are in the water.  Without fins, scuba diving would be nearly impossible, as the added weight and drag of the scuba equipment would make movement using just a swimming stroke almost impossible. Fins increase the surface area of t foot greatly, which means you can propel yourself along simply using kicks of the legs much more quickly and easily.  Fins make swimming down to dive sites such as wrecks and reefs and exploring larger areas much easier and more enjoyable so are essential items of kit for any diver.

7.  What fins are best for warm water diving?

If you are diving in warm waters some diver prefer not to be wearing wetsuit boots.  This means adjustable heel fins may be forgone in favour of full foot fins, as you can wear these without boots. The obvious drawback though, is that full foot fins for scuba do not protect the foot from anything sharp or venomous whilst not in the fin.  Full foot fins rarely fit perfectly and can move around when you are kicking through the water. To help keep full foot fins in place it is a good idea to buy some special fin straps to stop them from moving around.

8.  What size fins do you need?

Fins are available in a range of different sizes.  In terms of full foot fins you should choose a similar size fin to your foot size fins are constructed so that each fins cover 2 or 3 shoe sizes, this means a closed heel fin might be labelled 8-9 or 10-11 etc. Try to choose a fin where the sizing of the fin, falls across your foot sisz. I.e. choose a 9-11 size fins, if you foot was a size 10 and so on.  However as with shoes the same size fin from different manufacturers can actually differ in size, especially in terms of the width relative to the length, so you will need to try on fins to make sure they fit comfortably.  When it comes to open heel fins, the fins are sized in bands, such as small, medium or large.  The secure fit is achieved by getting an exact fit to your foot with the correct wetsuit boot size, then tightening the fin from the nearest size band to the boot by mean of the adjustable heel strap. This give a far superior fit which increases the efficiency of the fin kick due to the fact that there is little or no play in the movement, dur to loose fitting fins as with some closed heel fins. The size bands for Open Heel fins can vary a lot so you will need to refer to each manufacturers sizing charts and make sure you try the fins on with your wetsuit boots to ensure the right fit. 

9. Why are there high wall rails along the outside fin blades?

The rails that run along the length of the edge of the fin blade are there to prevent water from spilling straight off the sides of the fin when you are kicking.  This helps you to displace more water with each kick and makes your blades more efficient at propelling you through the water.

10.  Is there any fin blade colour which is better than the others?

It is a good idea to choose a brightly coloured fin blade as this will make you more visible to other divers and water users.  Also if you drop your fin or it falls off when you are underwater you will be able to see where it lands more easily.  There is a myth that certain fin blade colours will attract marine life but there is no evidence for this.  Fin blade colour is really just a personal preference and most divers just get the blades that match the rest of their equipment.