One of the most interesting aspects of the Mares Fleshell fondable mask is its combination of a record-low internal volume of just 74 cc, measured and certified by Apnea Passion Magazine, and an ingenious self-equalizing system. We have not yet completed our in-water test, but the characteristics of the Mares Flexshell suggest that it may require very limited mask equalization, even during deep dives. Let us first analyze its construction and technical features.
Frameless and fully foldable design
The Mares Flexshell Foldable mask has a frameless construction, meaning that the lenses are bonded directly to the silicone skirt without a conventional external frame.
Most frameless masks still feature a central chassis connecting the two lenses and providing a more or less rigid structure. The central section of the Mares Flexshell, however, is completely soft and flexible, allowing the mask to be folded entirely. The lenses are its only rigid components.
This construction results in an extremely compact mask that can be stored easily and take up minimal space.
Self-equalizing skirt
The most ingenious feature of the skirt is the combination of extremely soft silicone and a special flexible membrane positioned in the forehead area.
This design allows the skirt to compress vertically as external pressure increases with depth, without creating discomfort for the diver. As the skirt compresses, the mask’s internal volume is gradually reduced, helping to balance the internal pressure and limiting the need to blow air into the mask.
The combination of its record-low internal volume and self-equalizing system should significantly reduce the need for mask equalization during deep dives. We will soon test the system in the water with the Apnea Passion athletes.
Attention to detail
Beyond its self-adjusting system, the Mares Flexshell demonstrates excellent attention to detail. Its streamlined profile is highly hydrodynamic, helping to reduce resistance during descent and ascent.
The inner surface of the skirt has a matte finish, which helps reduce distracting light reflections reaching the diver’s eyes. However, the sealing edge is glossy, ensuring better adhesion to the skin and consequently a more effective watertight seal.
The wide nose pocket is designed to offer maximum comfort, including for divers with larger noses. Its external sides feature a textured grip area that prevents the fingers from slipping while pinching the nose during equalization.
Finally, the rear strap has a double-band design that distributes pressure evenly and keeps the mask securely positioned on the head. The strap can also be cut to allow the snorkel to pass behind the head, close to the nape, where it remains more stable and is less likely to vibrate.
Record-low internal volume
Last but definitely not least, the internal volume certified by Apnea Passion Magazine is just 74 cubic centimetres, making the Mares Flexshell the best mask we have ever measured in this respect.
Apnea Passion Magazine is the only organization able to measure the internal volume of any mask independently and precisely, providing directly comparable values.
Dimensions and weight
The ultra-compact Mares Flexshell has a maximum width of 15 cm and a maximum height of 9.5 cm.
The lenses are also extremely compact, particularly in the vertical direction. Each lens has a maximum width of 4.4 cm and a height of just 3.1 cm.
With a weight of only 120 grams, the Mares Flexshell is also among the lightest freediving masks currently available.
Conclusions
With its Record-Breaking internal volume, ingenious self-equalizing system, exceptional compactness and low weight, the Mares Flexshell appears on paper to be a potential must-have for deep freedivers. The main compromise is likely to be a more limited vertical field of view, due to the particularly compact lenses.
The Mares Flexshell Foldable mask is available exclusively through the Mares website for €39.95, including free shipping. Considering its technical features and innovative construction, it appears to be a particularly attractive offer.
