Finning technique in Spearfishing and Freediving



This is a wide and difficult topic. There are a lot of factors to take in mind, like the constitution of each one’s body, the features of the fins and the conditions in which they will be used. But, with any doubt, this is a key skill in spearfishing or freediving. It’s useless to have top gear if we don’t know how to use it or if it’s not suitable for what we need it. 

For this we are going to try to learn how to fin, correct some common mistakes that are often done in the beginning or if we use gear that is not appropriate for us. So, we will talk about the different factors that affect the finning, from the material, our body shape, weight, fitness, type of fishing… so in the end we can decide which fins are better for us. Let’s start talking about the fins.

 CKV carbon fins


Of course, to be able to fin, we need fins. For spearfishing and freediving they have long blades and closed footpocket. They give us a better foot fastening, and give us better performance, momentum and speed (compared with short scuba fins, which are designed to move heavy weights with slow speed). 

We can find them in different materials: plastic, carbon, composites… but today we are not going to talk about this (we are already writing an article addressing this topic and it will be published soon). We are only going to see the features of the fins and their stiffness. 

Salvimar System oneFoot-pocket: it has to hold our foot properly. It has to fit without being too tight. It’s also highly recommendable to always use fin holders. And always with the sock thickness we often use. If it is too tight it can stop the blood circulation and be uncomfortable (it can also cause injuries). And if it is loose, we will not make a good use of all the power delivered by the blade (and the fin could even go out of our feet). It has to be flexible and send the energy to the rails and the blade. 

Rails: They give stiffness to the back part of the blade. There is almost no reaction on this section of the blade, and it only propels due to the pushed water. Thin and short rails put all the stress on the blade. For example is good on carbon blades (good ones), because they were designed for that. If the rails are too stiff, they affect the stiffness of the blade. Due to this, changing the foot-pocket makes changes on the fin’s performance. 

Angle: the angle of the fin is something very discussed lately. Smaller angles (flatter fins), other ones way bigger… They have an impact on the position in which the fin works. The ideal situation is when the fin stays as an extension of our body, drawing a straight line. And here is important our ankle’s flexibility. If we can straight them a lot, a fin with a flatter angle will be better, other way it would go “to the back” and going out of the water, for example. If we can not straight the ankle, we will need more angle… The key point is that when we are in the water, with our legs straight and starting to fin, the fin becomes an extension of our leg. It shouldn’t go forward or backward. 

The angle must be the right for us. Not too much. Not too less
The angle must be the right for us. Not too much. Not too less

Blade: the “flat” part has its own characteristics regarding to reactivity, strength… It bends and, when we end the finning movement to start pushing in the other way, the blade itself keeps pushing due to its reactivity. 

C4 Mustang, a different footpocket
C4 Mustang, a different footpocket

Stiffness: When we talk about stiffness we are talking about how easy the blade gets bended. It can be soft, medium or hard. A soft fin will bend easily. For a medium one we will need a bit more of effort, and for a hard one, even more. This means that a soft one will be moved with little effort, without having to push too hard. And with a hard one, we will need more strength. But there are more factors related, and we will see them later. 

Shape: There are a lot of differences when we talk about the shape of the blade. Ones are narrower, others are wider. Different shapes on the end… It will affect the ammount of water displaced. We are not going to enter into this topic, because it would be too broad and also dependant of personal tastes and opinions. 

Each fins has a different shapes
Each fins has a different shapes

The most important thing related with a fin is to choose it right, according to our weight, body shape, type of fishing and stiffness. 


Each spearfishermen/spearfisherwoman is different, so the fins have to be appropriate to each of them. 

Weight: the weight affects they fin we need straight away. A soft fin, trying to move a heavy diver, won’t be able to work. It will get bended (because we put the needed effort), it will displace water (according to the effort we put), but if we are too heavy, it’s possible that we only get a small movement. The opposite case, with a hard fin and a lightweight diver. We push during the finning, and besides it needs more energy than a softer one, the fin starts to bend. But it doesn’t bend as much as it should, and it doesn’t give us enough movement. We don’t get to use the power that the fin could deliver, and we also get more tired and we put more stress in our ankles and our joints in general. 

This happens when we feel that we need to bend our knees too much (we will talk about this when we talk about finning technique). 

With a proper fin related to our weight, we will make the effort needed to bend the fins on its optimum point and start moving. The fin itself will keep pushing us with its reactivity. We will see that we move a lot with little effort. And we will be able to keep our legs with the minimum angle to fin (more hydrodynamic position). footpocket

The body shape and fitness level its also related. Someone who is trained, with better finning pace, would be able to use a slightly stiffer fin. With this, it’s possible to get a little bit of extra push, specially under situations like going fast from the bottom or fishing under the breaks… 

The finning pace is also important. Some people like more a slow and wide pace. Other ones prefer a shorter and faster one. 

They are things to keep in mind when we choose the fin. 


It’s other of the key points to choose the stiffness and the fins.  First we will choose by weight and body shape. Now, according to the type of fishing, we will fine tune our election. 

For a fishing in which we stay a lot of time on the surface, with a lot of swimming, sometimes with currents, slow stalking in the bottom… is better to choose a softer fin. Specially when we swim a lot on the surface, for extended periods of time. A softer fin (inside the range of suitable fins for us) will make us less tired and it will not stress our ankles. We will lose a bit of reactivity and strength for certain moments (like exiting from a break), but we will win in comfort and stamina. Exactly the same for those who are starting or untrained. A bit softer is better. comming to the surface

For deep spearfishing is better to go for soft to medium fins. Finning with less effort, to keep the pace and consume less oxygen, without making us tired. 

For spearfishing in the swell specifically, is better a harder fin. It gives us the chance of making a small over effort in a certain moment to be able to fight with that wave that is coming. A softer fin would be worse for this situation. 

As we can see there is not a fin which is the best. It’s something very personal, depending on each fishermen and each type of fishing. 

As a summary, we can advice that for fishing from the shore, with a lot of swimming, it’s better to go towards something a bit softer than we would need just looking at our body shape. If we go from a boat, only diving in the spots in which we are going to fish, we can use something a bit harder, as we would do for fishing in the swell. And the better trained we are, we can raise a bit the stiffness. 

Of course, after all of this, there is people who prefer harder or softer fins. But we will see this with practice and experience. This article is just an introduction. 


Now we are in an important topic. Because it’s useless to have a good pair of fins, according to our needs if we don’t know how to use them. Finning is not just moving our legs up and down. There is more. And the difference will be to get a lot of movement with little effort or the opposite, and thinking that the material we have is bad. 

Let’s start seeing what is the finning. There are 3 stages when we fin:

finning– pushing the fin down

– neutral point

– pulling the fin up 

During the first one, we push downwards. The muscles used are the quadriceps and the hamstring muscles. We have to try to straight the ankle as much as we can. And we push. It’s the most well-known part of the finning, and almost everybody does it. Here, we push water, just with the movement, and this is what moves us. 

Then, when we reach the end of the movement, with the fin bended, it goes to the starting position by itself, and it keeps pushing until that point (pic in the middle). We have to allow it to do this work, and not go to the next stage right after finishing the first one. 

The next stage is as important as the first one, and a lot of people forget about it. It’s the movement of pulling the fin. We use the calves and the biceps femoris mainly. If before we were pushing downwards (if we are in horizontal position), now we pull the fin up. It’s the opposite movement. If we don’t do it and we just get the leg to the starting position to push again, we are wasting half of the finning and half of the movement. 

And also, if we adjust this both stages, while one is pushing in one direction, the other one can be pulling in the opposite, keeping us balanced. We advance more and we reduce the effort by keeping a constant speed.

 aleteo-biciBicycle kick: we have to avoid it always. It´s less hydrodinamic. It´s usuall when we are using fins too hard for us or when we don´t have a good technique. 

Another common mistake, specially when we ascend, is to fin doing a “bicycle kick”. The finning has to be with the legs straight, with the minimum angle on the knee, to avoid tensions there. But never bending the knee too much. This causes a less hydrodynamic position, and gives us less performance because the fin is not working properly.  

angulo-piernasThe finning has to be with the legs straight, with a minimum angle in the knees and matching both stages (we push with one leg and pull with the other one at the same time). 

Sometimes, this mistake comes from using a fin that is too hard, that makes us bend the knee to bend the fin. In other cases, it’s just a defect in the diver, because this kind of kicking seems easier. It’s something we should avoid. 

It will be a movement with the legs almost straight and fluent, without stops in between. We can get more speed when we do this and also keep it constant. We get less fatigue and we will use 100% of the power given by the fin. It’s like a scissor move, and we should never do it as a pedalling move “suppoting” ourselves in the fins. 

Another important key-point is to keep a horizontal (or vertical) position and stay totally aligned with the movement we are doing. Don’t stay sloping. You can see it in the picture. proper position in the water in spearfishing

The body position has to be horizontal in the water (or totally vertical when we ascend or descend). We will create less drag when we advance and we will gain more speed with less effort. 

We will be more hydrodynamic doing this. The surface that offers resistance to the advance has to be the minimum. Although it can seem a small detail without importance, it’s something really important. The same descending or ascending. Always keep a vertical position. 

The head has to be looking forward, without stretching the neck to look to the bottom or to the surface. The neck has to be in a relaxed position, without tension. 

As we can see, these are some easy things that will improve our performance a lot while moving underwater. 

And regarding to choose the fins, we can see that it is not that easy. It’s not about asking which ones are the best fins. The question is which ones are the best fins for our needs. In plastic fins we will look for the appropriate stiffness of all the fin (blade + foot-pocket) and not just the blade. 

And the same with carbon, where we can normally choose between different stiffness levels. Talking about craftsmen, a lot of them give us the choice of making them custom made. For example CKV FFSUB gives us a small list with questions, to gather data about our weight, height, type of fishing… and they make the fins according to this information. 

Any question or advice you can leave a  comment.

[vc_btn title=”Looking for the best carbon fins at the best price? Contact us!” color=”primary” align=”center” link=”||target:%20_blank|”]