Before purchasing your fins, you should know how to size them. Typically, there are two sizes of fins, and each size is roughly equivalent to a pair of shoes. However, some fins may span two or even three sizes, so you should take your shoe size into consideration as well. For example, if you wear shoe size nine, you might find that your toes stick out of the foot pocket of the fin, so you should switch to a size larger.
Choosing the right size for fins is a very important part of surfing. Your fins account for nearly 50% of your wetted surface area, so choosing the right size is imperative to maximizing your surfing performance. Fin size charts can help you choose the perfect set of fins, but they aren't always reliable and cannot cover all your surfing needs. When in doubt, buy one size larger than your regular shoe size.
The shape of a fin will determine the way it works with your board. Generally, stiff surfboards pair better with small, flexible fins, while soft, flexible boards are best matched with large, wide fins with plenty of sweep. A fin set can be referred to as a cluster, and their placement on a surfboard affects your surfing performance. A larger number of fins will result in greater drive and hold.
Before you purchase a pair of fins, check that they fit correctly. Fins are unisex and have sizes that correspond to shoe size. You may want to wear neoprene socks or dive booties when you're trying them on. Dive booties can be different thicknesses, and a thicker pair is better for cold water. Fins that rub or don't fit properly may need to be sized up.
The best way to determine whether or not your fins fit is to try them on. A pair of fins should fit snugly over your foot and not restrict your movement when you walk around. A pair of full foot fins should fit snugly but not restrict your movement. Try walking around in them before you purchase them. Make sure that you don't feel restricted while swimming. You should also try them out in cold water, as a tight fin can cause cramps.
If you haven't tried on dive fins yet, you're missing out on one of the most important aspects of water diving: comfort. Fins should fit your feet snugly, without pinching or chafing. Fins that are too large or too small will slide off your foot or cause blisters. Also, be sure to purchase fin socks to avoid chafing. This way, your fins will stay on your feet and you won't have to worry about slipping them off while swimming.
Fin foot pockets vary between models. Check the sizing information on the fin you're considering. Some fins are specifically designed for barefoot divers, while others are meant to be worn with dive boots. To determine the size of your fins, stand barefoot in the store and raise the fin tip. If you struggle to lift the fin tip, then you've chosen the wrong size. Make sure your fin fits snugly, but not so tight that you can't breathe.
One way to make sure your fins are adjustable is to try them on. Ideally, your fins should fit snugly on your feet, and be able to be easily removed or put back on. If they slip off during use, they may be too large or too small. If they are too loose, they can slip off while swimming, causing discomfort. Similarly, fins that are too tight may cause blisters or chafing.
Depending on the type of fins you have, you can adjust the amount of flex. Adjustable fins are usually more rigid and uncomfortable than others. You'll have to wear booties when you go for a swim, but these fins are convenient for getting in and out of the water. If you're not sure whether your fins are adjustable, buy a spare pair to be on the safe side.