Freediving fin booties come in a variety of types.
Of interest are the Salvimar Delta One K-Reinforced, the anatomical C4 and the Pathos.
Let’s start with the former.
Thermoplastic or natural rubber, traditional or super anatomical shape, differentiated thicknesses or inserts embedded in the rubber, there are many solutions on the market.
Important to know that, especially when using high-performance (and cost) paddles, such as those made of carbon fiber, it makes no sense to use low-quality booties that do not transmit well the force exerted by the leg and foot of the angler or freediver.
For high-performance paddles, there needs to be adequate booties with a high level of construction, both in materials and design.
Salvimar’s solution with the Delta One K-Reiforced is very interesting.
If from a high C4 in fact revolutionized the market with the super anatomical and asymmetrical booties, with revolutionary attachment also for the paddles, and Pathos designed the first traditionally shaped booties specifically for carbon paddles, Salvimar made a great study working on the traditionally shaped bootie, but optimizing materials and geometries. First of all, the Delta One K-Reinforced bootie uses natural rubber 55 Shore hardness, a material that maintains mechanical characteristics (hardness and elasticity) over time, without deforming or hardening.
In addition, natural rubber, unlike thermoplastics, does not undergo degrees of changes in hardness with temperature.
Indeed, it is true that many low-quality booties harden in winter with low water temperatures (14-15°), while they become too soft in summer with sea water above 25°C.
The stringers, on the other hand, are made of natural rubber 80 Shore hardness to give more texture to the connection with the blade.
The top-of-the-line Salvimar bootie (there is also a cheaper thermoplastic version, called Step) has as an extremely innovative and clever feature a band of Kevlar embedded in the natural rubber at instep height, right there where most of the buoyancy is transmitted from the foot to the bootie and the blade.
Because Kevlar does not stretch, in fact, the bootie on the instep, while remaining soft, with rubber of not too high hardness, transmits all the thrust possible to the shovel.
From this solution comes the name K-Reinforced.
Salvimar Delta One K-Reinforced bootie sectioned and cut where the Kevlar instep band is visible. Adding to the solutions described above is the use of different thicknesses depending on the foot area.
The production process sees a molding of the upper part of the bootie and an injection of the lower part.
Finally, the bootie has a special interlocking system of the shovel, with a plastic insert that provides an excellent connection between the bootie and the shovel, thanks to the reduction of clearance.
The back has V-shaped profile to help insert the heel.