Leaderfins is one of the most important international designers and manufacturers of freediving and spearfishing fins, but also fins for underwater games and life saving and, more recently, freediving and spearfishing wetsuits. The company based in Estonia has an amazing line of spearfishing and freediving fins. As we have seen some time ago, these include blades of 3 materials, full carbon, sandwich (external carbon and internal glass fiber) and glass fiber, 2 angles, 20° and 33°, and 3 lengths, 60, 70 and 80 cm. Thanks to this incredible range of fins, and with the help of the amazing Y-40 The Deep Joy pool, the deepest thermal pool in the world, we have been able to bring forward extremely analytic tests. The first test has been the analysis of deep dives with the 3 different lengths of carbon fiber fins. To make the tests our great Champion, Luciano Morelli.
Testing process
Utilizing the area of the Y-40 which goes down to the record depth of 42.15 meters, we have used with Luciano Morelli the dive line to make multiple and consecutive dives changing the fins used. The constant conditions of the pool have been key in the analysis of the dives. Utilizing the Cressi King, winner of the Best Choice by Apneapassion 2023, each dive has been studied on the Cressi App to verify the speed of the dive in each instant. In particular, the dives have been analyzed in the restart from the bottom, checking the capacity of the fins to push Luciano back up in the point where the speed is zero and the negative asset is at its highest. This is where the acceleration of the fins can be best evaluated. After the first three meters of ascent, the speed is again checked to understand the velocity that can be achieved after the initial acceleration. In addition, due to the fact that a dive is linked to the intensity of the kicks and the technique used, Luciano has also counted the kicks to ascend from every dive.
80 cm blade length
The fins used and the dive
The 80 cm carbon fibre blade Leaderfins, which are by the way particularly accessible economically, were equipped with the Leaderfins Forza footpockets. The stiffness of the blade utilized for this test has been Medium. The angle between blade and footpocket was 33°.
Following the vertical line, Luciano has dived to almost 40 meters, just a little less considering the need to turn at the bottom, position himself vertically, and restart from still, with the Cressi King on the wrist.
Time, kicks, acceleration and speed
In the dive with the 80 cm blade fins Luciano has needed 53 kicks to ascend from 36.9 meters, with a total time of 42″.
After 2 meters coming up from the maximum depth the speed has been 0.70 m/s, an extremely good value. The speed after another 2 meters, which then becomes quite constant, is measured with the Cressi King equal to 0,78 m/s, also a good value as “maximum speed”.
No delay in the Cressi graph is visible in the restart phase from the bottom.
Comment by Luciano
“The 80 cm 33° carbon fiber Leaderfins are extremely fluid, confortable and efficient. The acceleration from the bottom is very good, and the speed is definitely excellent”
70 cm blade length
The fins used and the dive
The 70 cm carbon fiber blade Leaderfins, have the same stiffness (medium) and angle (33°) as the 80 cm, so all parameters, except the length, are unvaried. The constant conditions of the Y-40 are also key to keep all the parameters unvaried.
Time, kicks, acceleration and speed
In the dive with the 70 cm blade fins, Luciano has needed 56 kicks to ascend from 36.8 meters, taking him 46″.
But let’s analyze how the speed of the 70 cm fins has changed compared to the 80 cm. After 2 meters from the maximum depth the speed has been 0.68 m/s, so slightly lower than the 0.70 m/s of the 80 cm ones. The speed after another 2 meters, which again becomes quite constant, is measured equal to 0.74 m/s, a significant reduction compared to the 80 cm blades (0.78 m/s).
A slight delay is visible with these shorter fins in the phase of restart from the bottom.
Comment by Luciano
“The shorter blade of 70 cm of length requires narrower kicks compared to the 80 cm. Definitely the 70 cm are more “agile” than the 80 cm, but still the general feeling of performance is higher with the latter”.
60 cm blade length
The fins used and the dive
The 60 cm carbon fiber blade Leaderfins, have the same stiffness (medium) and angle (33°) as the 70 and 80 cm, so again all parameters, except the length, are unvaried.
Time, kicks, acceleration and speed
In the dive with the 60 cm blade fins Luciano has needed 61 kicks to swim up from 37.0 meters, with a total ascend time of 46″.
Again, let’s analyze where the speed of the 60 cm fins has varied compared to the 70 and 80 cm. After 2 meters from the maximum depth the speed has been 0.67 m/s, so lower than the 70 (0.68 m/s) and 80 cm blades (0.70 m/s). The speed after another 2 meters, which again becomes quite constant, is measured equal to 0.72 m/s, significantly lower than the two longer blade fins (0.74 and 0.78 m/s).
Again, quite similarly, but more evidently, to the 70 cm blades, for the 60 cm blades the Cressi graph shows a delay in the restart from the bottom.
Comment by Luciano
“The 60 cm fins are unexpectedly nice and with a great feel of lightness on the feet and the legs. The restart from the bottom is still good, while the maximum speed is ceilinged. In fact, even increasing the speed of the kicks, the feeling is that the ascent speed does not increase.
Conclusions
| Length (cm) | Material | Angle | Depth (meters) | Ascent time | Kicks | Restart speed | Top speed |
| 80 | 100% Carbon | 33° | 36.9 | 42″ | 53 | 0.70 m/s |
0.78 m/s |
| 70 | 100% Carbon | 33° | 36.8 | 46″ | 56 | 0.68 m/s |
0.74 m/s |
| 60 | 100% Carbon | 33° | 37.0 | 48″ | 61 | 0.67 m/s |
0.72 m/s |
Putting together the data acquired by the Cressi King, it is quite evident how performance decreases with the reduction of the length of the blades, while agility improves. This performance reduction, though, is limited in the acceleration phase, and more evident in the top speed. In the acceleration from the bottom, the more critical aspect is the the fact that shorter fins have a slight delay in increasing speed if one wants to keep a calm kicking activity, as it is done in freediving. Still, short fins quickly recover speed after this short delay. Luciano Morelli has confirmed that shorter fins impress for their lightness and agility, giving the opportunity to quickly increase the speed of the kicks. At the same time, though, such action determines an increase in speed only to a certain limit.
