Introduction
The Mantra fins are among the best options for both spearfishing and freediving by Cetma Composites. They are designed to deliver a perfect balance of performance, efficiency, and comfort. Their innovative construction and advanced technology make them suitable for athletes and passionate divers looking for a fin that performs well in recreational but also more competitive settings.
Materials
The MANTRA fins are made of high-quality Prepreg carbon fiber, ensuring a highly resistant structure. This material choice provides the perfect balance between durability and performance, allowing divers to enjoy long sessions in the water without compromising efficiency.
Design
The Mantra is a strong and progressive fin, designed to guarantee excellent performance in various underwater conditions. Their 33° blade angle differs from the 27° of the sister fins, the Cetma Mantra CWT Competition. It has been carefully engineered to make surface swimming easier, even in strong currents, reducing strain on the legs and optimizing comfort.
The Cetma Composites Mantra fins are meticulously crafted for both spearfishing and freediving, emphasizing performance and diver comfort. The dimensions of the blade measured by Apnea Passion are:
Length: Approximately 70 cm (27.6 inches) from the bending angle.
Width: Approximately 19.5 cm (7.7 inches).
Angle: 33 degrees.
Dynamic Resonance System (DRS)
The Dynamic Resonance System (DRS) is an innovative technology developed exclusively by CETMA Composites to enhance the performance of the MANTRA fin blades. This system is engineered to allow the blade to resonate within a specific range of finning frequencies, thereby optimizing propulsion efficiency.
Resonance is a physical phenomenon where a structure, when subjected to a force at its natural frequency, exhibits increased amplitude of vibrations with minimal damping. By meticulously designing the distribution of stiffness and mass, CETMA Composites has “tuned” the MANTRA blades to align their natural frequencies with common finning frequencies. This alignment enables the blades to enter resonance during use, resulting in significantly enhanced propulsion with reduced effort.
The development of the DRS involved advanced engineering techniques, including modal analysis performed with a laser Doppler vibrometer (LDV). This analysis was crucial in determining the optimal mass and stiffness distribution across the blade, ensuring that the resonance effect is effectively harnessed during finning.
In practical terms, divers using fins equipped with the DRS experience lower muscular fatigue and greater propulsion efficiency, as the fins work in harmony with the natural dynamics of finning. This technology represents a significant advancement in fin design, offering divers improved performance and comfort.
Water rails
The water rails are in silicone and have a variable height design for best performance. Additionally to all other fins on the market, not only do the water rails act with a greater height at the tip of the blade, but they also connect with an increased height also on the side of the S-Wing footpocket. The latter, in fact, has a special design with a flow channels to direct the water since the tip of the footpocket all along the blade. This improves water flow, reduces turbulences and increases the the quantity of water sliding on the blade. The result is a reduced friction, better thrust and efficiency at every kick.
S-Wing foot pocket
The MANTRA fins are paired with the S-Wing foot pocket, designed for maximum energy transfer and comfort. The ergonomic fit ensures stability during powerful kicks, while the structure enhances hydrodynamics, minimizing energy dispersion.
Weight
The measures by Apneapassion indicate a total weight of the Cetma Mantra CWT competition, with 43-44 footpocket, of 910 grams. The blade, very light, has been measured 295 grams. The construction from 100% IM7 carbon fiber makes this blade very lightweight, enhancing propulsion efficiency and reducing diver fatigue.
Blade Stiffness Options & foot pocket Sizes
The MANTRA fins are available in four different stiffness levels—Xsoft, Soft, Medium, and Hard—making them versatile for different body types, preferences, and diving disciplines. Whether for dynamic freediving, depth training, or spearfishing in challenging conditions, there is a suitable option for every diver.
The fins also come in a wide range of footpocket sizes, ensuring a precise fit for improved comfort and performance. These are 35-36, 37-38, 39-40, 41-42, 43-44, 45-46, 47-48. The size chart to chose the correct foot pockets is found on the Cetma Composites website.
Finning technique
To leverage the DRS, freedivers should adopt a finning style with a frequency that aligns with the blades’ natural resonance. This synchronization maximizes thrust while minimizing energy expenditure. Of course the Cetma Mantra are designed so that the finning rhythm optimized to match the resonance frequency is a wide range to make it easy to reach an optimal finning period. The 33° angle optimizes surface transfers.
Conclusion
The Cetma Composites MANTRA fins combine cutting-edge materials, innovative design, and advanced technology to deliver one of the most versatile and best-performing fins on the market. Whether you are a freediver or a spearfisher, the Mantra offers power, efficiency, and comfort in every kick.