Bi-Fin Technique for Freediving

Text and Photos by AIDA Master Instructor Yoshua Surjo

In this article I would like to convey my personal thoughts on the most efficient technique to use with bi-fins. Fin kicks can make a huge different in our diving: An efficient fin kick propels us further in shorter time with minimized effort. The more efficient we are in our movements, the deeper we can potentially dive or prolong our bottom time.

I believe there are two major parts that characteristic for most efficient fin kick. These are:

– Leg position and movement

Bi-Fins technique

– Amplitude and frequency

The best leg position during a fin kick is a straight legs. To reach this position you will have to lock your knees and ankles. The easiest way to imagine it is when you are tip toeing just like a ballerina. The front kick and the back kick should be symmetrical and well balanced.

Now that we covered the leg position and movement, we are going to discuss the amplitude of our kick and the frequency. The amplitude of our kick is basically the wideness of our kick while the frequency is “kicks per minute”.

The amplitude and frequency of our kick depends on the length of our legs and the characteristics of the fins we are using. If you have a long legs, most probably you will be more suitable with softer blade and vice versa. And if you use a soft blade, your amplitude should be small with a higher frequency. Vice versa, when you are using a stiffer blades, your kick amplitude should be bigger with a lower frequency.

To soft or too hard?

If your fins are too soft, wide kicks will create more drag while the blades are fully bent. In this position the fins will no longer generate maximum power and you will need a higher frequency of kicks to prevent you from losing momentum.

On the other side, if your fins are too hard, you will need bigger amplitude to get the maximum out of your blades.

Written by: Yoshua Surjo, AIDA Master Instructor