BLACKTECH SHARK SKIN

ANTI GLARE CARBON FINS

Last fall I submitted an article about a young Croatian company specialized in the production of carbon fins: the BlackTech. I always pay attention to the new pieces of spearfishing equipment launched on the market and I got impressed by the innovative product that the company above made.

The carbon fins have become very popular among actual spearos all over the world and during the last few years this product has evolved exponentially. Many different blades are in fact available on the market; larger, longer, with flap tip, with whale's tail tip, variable thickness, fixed thickness, etc. but no one has ever focused on solving a problem that all these types of fins have in common: the reflectance.

The carbon fins manufacturing requires the use of fibers and resin and the latter is right the ingredient providing the surface with a glossy look. We all know how negatively a reflex can affect the Spearfishing action and as a consequence some manufacturers have started to apply water resistant paints on the fins that clearly affected the mechanical properties of the material used in favor of a more eye-catching look.

The BlackTech has taken into account the main features actually offered by the market when designing  its product, a project that took three years to be finished. The two naval engineers Sasa and Bruno, who have been assisted for the tests by the local Spearfishing community, have created variable thickness carbon blades with a special “honeycomb” – like surface that guarantees absolute discretion in water, in other words, all the benefits of a carbon blade with the reflectivity of one made of  techno-polymer! Let's go through their features.

MEASURES

The blades are 80cm long and 19cm wide and are produced with a 22 ° angle. They are provided with T-shaped side rails suitable for any foot pocket and which widen only at about two-thirds of the length of the blade in order to affect as little as possible the flexibility of the carbon and avoid the fin to skid during movement.

TIP 

The tip, as you can see in the picture has a whale's tail shaped tip but the manufacturer provides six different types and is also available to the customize the tip according to a design submitted by the customer. The most common types are that of the model in the picture (particularly suitable for spearfishing since it does not protrudes beyond the fin silhouette) and the "flap" one that ensures a better grip on the water and a greater thrust but which can create difficulties when fishing on the rocky seabed.

THICKNESS AND ORIENTATION

The thickness of the blade is variable, this means that it gets progressively thinner towards the tip. It is in fact designed to get thinner from the two thirds of the length on but its peculiarity lies in the orientation of the fibers that does not follow the classical scheme of the fins currently available on the market. If you look at the common blades with variable thickness you can easily notice some semicircles that demarcate precisely the difference in thickness between the various layers. This layout generates “steps” that represent points of greater mechanical stress and that, according to the quality of materials used by the manufacturer, could become potential points of breakage. Unfortunately BlackTech, for obvious reasons, has requested to not publish further details about it but I can tell you that he found another way to lay the fibers which reduces the "step" between the different thicknesses.

MATERIALS AND PROCESSES

The BlackTech uses carbon fibers specially produced for aircraft industry and a special epoxy resin, manufactured in Germany, whose the most important feature is represented by a high modulus of elasticity capable of giving great flexibility to the final composite product. The production takes place through a double infusion process ensuring an accurate expulsion of air potentially present between the layers, and that would be a source of structural weakening. According to the manufacturer this process provides greater guarantees than PregPreg technology.

HARDNESS

The Croatian firm is completely customer-focused  in fact further to several types of tip anybody can choose his best fin among 9 different levels of hardness. In the market we usually find the standard soft, medium and hard blades but how many times the hard ones were too hard and the medium ones were too soft? Well, it’s for this reason that Blacktech offers such a wide range!

TEST

I mounted the blades in the Salvimar foot pockets and they get so tight that there might be no need to glue or drill them since they don’t slide away even if you pull them horizontally. I recommend such a foot pocket also for the angle of 22° which utterly assist the original curvature of the blade. In addition, the slit of this foot pocket allows to get a more powerful thrust with the front of the foot (metatarsal) without forcing the ankles. This structure, however, demands a perfect athletic movement because it does not leave any room to kick close to the “cycling” style. The flexibility of the fin is indisputable, it can be easily folded and squeezed. The spring back is remarkable even if it is a low hardness model. It 's definitely a fin suitable for long surface swimming as it does not tires the articulations and for spearfishing in average depth where it is necessary to get responsiveness and agility from a fin. In the water there is no reflection at all and thanks to their unique surface normal scratches that are generated by rubbing against rocks tend be not that visible. These fins are truly exceptional, considering that they are also used by some member of the Croatian national spearfishing team, those are Branko Ikic and Radoslav Jakupovic who have achieved excellent results in recent international competitions.

Blacktech is distributed in Italy by DIVEBLU BARI