The Cetma Lotus, the polymer blade fins by Cetma Composites, fully designed, engineered and manufactured in Italy, have undoubtedly been the first advanced “plastic” solution on the market. They have put together a modern foot pocket, the S-Wing, containing an incredible number of strong mechanical advantages, including the short side rails concept, with a polymeric micro-composite material combined with a differentiated stiffness distribution blade. Let’s discover how much technological content there is in the Cetma Lotus, as nobody has ever told you.
Blade material and design
The polymeric micro-composite material is the base of the advanced blades of the Cetma Lotus. The concept of this material is a polymer material with reinforcement. The polymer acts as a matrix resin that penetrates the reinforcement bundles and bonds together. This solution generates a strong and reactive material, which performs noticeably better than previous-generation polymers. With this new material, the performance of the fins moves to a higher level, reducing the gap with composite materials such as carbon fibre. The blades are available in white colour and black, light blue, magenta and gold logo, or in black with the same colours except gold.
Blade stiffness distribution
The blades of the Cetma Lotus are not only advanced due to the use of advanced polymeric micro-composite material. Another key element of their performance is the design, which is based on the variable stiffness distribution. The blade has in fact a very detailed design, where its thickness not only changes along its length, but also between different areas. There is, for example, a central band, wide in front of the foot pocket, and narrower towards the tip of the blade, which is thicker than other areas. The values go, as measured by AP, from 3.15 mm to 2.50 mm. The areas of the blade with a nice texture look surface, have a reduced thickness compared to the central band, going from 2.70 to 2.00 mm. This slight, but important, thickness variation is also visible in bare eyes.
The curved area at the start of the blade has three reinforcement nerves in the inferior part for greater stiffness and resistance.
Water rails and flap
One of the key aspects on which take care with fins is the control of the lateral slide. To obtain this water rails and the design of the flap are at the base.
The water rails of the Cetma Lotus are one piece with the blade. There are two main ones, with variable height progressively reaching a maximum of 2 cm moving towards the tip of the blade. The total length of these water rails is 9 cm. Internally to the blade, only on the upper surface, two smaller water rails are present. They are 4.5 cm long and 3 mm high.
In addition, the flap has a convex V shape profile which is the design which better helps slide control.
Cetma S-Wing foot pocket
It is impossible to obtain great performing fins without a high-quality foot pocket, both for force transmission from the foot to the blade, and of course for the comfort. The Cetma S-Wing foot pockets have hit the market some years ago revolutionizing it. Since then, many companies have followed a lot of the solutions present in the S-Wing foot pockets. In particular, the Cetma S-Wing foot pockets have 9 key advantages
Deep socket for the blade
The Cetma S-Wing is designed to permit the rear of the blade to enter deep inside the inferior part of the foot pocket, generating a better transmission of the force from the foot to the blade. This is particularly evident with carbon fibre blades but also works with polymer blades.
4 stiffening bands
As a ski boot, the Cetma S-Wing have 4 stiffening bands, from the ankle to the final profile near the toes, which avoid deformation of the rubber and improve force transfer.
Stiff sole and heel
The base of the Cetma S-Wing foot pocket is stiff, including the heel, so there is no deformation also in such key area during the kicking. The force transfer is so greatly optimized.
Water flow channels
With the aim to improve as much as possible the water flow along the foot pocket and the blade, the Cetma S-Wing have two lateral channels. These reduce turbulence, and so friction, and also clean the water flow along the blade for better efficiency.
Vertical side stabilizers
For a better control on the kicking the foot pockets have two vertical side stabilizers, which control side drift and keep the water flow in the channels clean and without too much turbulence.
U-shaped structure
The U-shaped structure of the Cetma S-Wing foot pockets is stiff enough to avoid the roll of the blade during finning.
Wraparound fit
The Cetma S-Wing foot pocket is designed to perfectly wrap around the foot. Additionally, it is offered in 7 different sizes: 35-36, 37-38, 39-40, 41-42, 43-44, 45-46, 47-48.
Innovative rubber blend
The material of the Cetma S-Wing puts together the elasticity of the natural rubber with the durability of synthetic rubber. Even though today the S-Wing are not the lightest foot pockets on the market, they are still neutral in the water thanks to a density of 1.05 g/cc (water is 1.00 g/cc, seawater 1.02 to 1.03 depending on the salinity). The S-Wing is now available in three colours, black, red and white.
Adaptable to most blades
This foot pocket can be mounted on all Cetma Composites blades, and most of the blades of other brands. It can be connected to the blades utilizing two small screws or by glueing. The screws are very neatly matched with small round plastic washers.
Weight
The aim of Cetma Composites has been since the beginning to create a light fin, but not as the most important aspect. Before that, it is the performance and comfort to come first. Undisputable world Champions fins like the amazing Cetma Taras, or the new excellent Lotus Carbon, might weigh more than some competition but are clearly the best performers. The Cetma S-Wing foot pocket weighs (AP measures) 625 grams, including the connection clip, in size 43-44. Still, as said, it is neutral in the water. The Lotus polymer blade weighs 350 grams.
Easy move from polymer to carbon fiber
On top of the great performance and quality of the Cetma Lotus fins, there are key additional advantages that make these fins a great choice for beginners, but not only. The Cetma Lotus are designed to reproduce a very similar behaviour as the carbon fibre solutions by Cetma. In such a way, the beginner or intermediate can learn and improve his finning technique with the Lotus. After that, once she or he wants to move to a higher level of performance, reachable only with carbon fibre blades, the right technique will have already been acquired.
The second aspect is that the S-Wing foot pocket can host perfectly the carbon fiber blades by Cetma, so the diver will not need to buy new foot pockets, but only the blades. Finally, the polymer blades will always serve well for training or specific situations both in freediving and spearfishing, such as practising the latter in shallow water among rocks, where you don’t want to ruin your carbon fibre blades.
