The new H.Dessault Fast are positioned at a higher level compared to the already presented Minimal, which are instead a perfect value for money. Let’s see materials and technology of the Fast solution by the French brand.
Blade
Material
Made 100% in carbon fibre, with external layers of T700 fabric, the blades of the H.Dessault Fast fins are in top quality big squares fibre, a highly sought after material on the market. Such solution determines a reduced number of crossings of the fibre filaments, and so a much higher elastic return. Of course, the T700 material determines a slightly higher pprice compared to the H.Dessault Minimal fins. Additionally, the internal part of the blade has a T700 unidirectional carbon fiber texture that determines great elastic return and is a key element of the C4 Technology.
Shape and dimensions
The length of the blades is, measured by AP starting from the curve in front of the footpocket to the tip, 65 cm laterally and 63 cm centrally. The width of the blade, measured internally to the water rails, is 19 cm. 29° is the angle of the blade, which is then added to the 3° of the 350 foot-pocket, for total 32°.
The tip of the blade has a concave shape, which helps to control lateral slide and reduces the total length of the blade compared to a convex solution.
Water rails
The water rails are the Elastic-K10 black, with a half rounded profile, now used in all the C4 Family production and that, according to Marco Bonfanti, works particularly well. They run along all the blade, starting from the extremely short side rails of the HD 350 foot-pocket. The total height of the water rails is quite small, and equal (AP measured) to 15 mm.
Available stiffnesses and weight
The blades of the H.Dessault Minimal fins are available in 3 different stiffnesses: 25 soft – 30 medium – 40 hard. The weight of the 25 soft blade is 250 grams (AP measured), extremely low and 25 grams lighter than the H.Dessault Minimal.
350 footpocket
Reduced weight
The number 350 of the H.Dessault footpocket indicates the weight in grams of the number 41/42. Such aspect, the weight control, is a key element to which the “C4 Family“, C4 Carbon and H.Dessault, looks at with great focus when designing fins. We have weighed the size 42/43 (8.5-9), and honestly it weighs even less, 345 grams, excluding the connection elements to the blade. Well done H.Dessault!
Materials
The H.Dessault 350 footpocket is made using TPE 75 ShA polymer, a thermoplastic elastomer. Such material shows advantages typical of both rubbery materials and plastic materials. The benefit of using thermoplastic elastomers is the ability to stretch to moderate elongations and return to its near original shape creating a longer life and better physical range than other materials. The ShA code indicates the Shore A Hardness of the thermoplastic rubber, and the value 75 is a medium value. The use of such material according to H.Dessault permits a great transmission of the force from the foot-pocket to the blade of the HD Fast fins.
Design
Apparently similar to the C4 250 footpocket, with almost absent side rails, the H.Dessault 350 footpockets are designed in a simpler way with no integrated rigid sole. Such solution requires some additional rubber on the base to make it more less flexible.
In the inferior part of the 350 footpocket, starting from the side rails, two ribs go all along to the rear of the heel, becoming a key stiffening element of the base. The upper part of the footpocket has a thicker band which is narrower on the sides, starting from the base of the side rails, and becomes much wider on the instep. The band helps to stiffen the area and better transmit the force from the foot to the footpocket to the blade.
The angle of the 350 footpocket is the typical 3° by C4, which is added to the 29° of the angle of the blade, for total 32°. The finishes of this footpocket are very neat, actually better than the 250 we have seen so far.
Connection to the blade
The connection of the 350 footpocket to the carbon fibre blade of the H.Dessault Fast fins is the same as the C4 Umberto Pelizzari and the C4 250 fins line. There is one single screw with Allen head size 4 complete with threadlocker tightened in a self blocking brass nut embedded in a plastic element. The insertion of the carbon fibre blade in the 350 foot-pocket is amazingly simple and fast, and so is the tightening.
Conclusions
The H.Dessault Fast fins finally weigh only 595 grams per fin, a excellent result. They are a step up compared to the H.Dessault Minimal, as they use the more efficient T700 big squares carbon fibre material for greater elastic return and a finally lighter solution. The price of the H.Dessault Fast fins grows slightly compared to their cousins, the Minimal, going just above 260€ discounted on the web.
A possibility, for example, for those who have already bought the excellent HD Maxx, is to buy only the carbon fiber blades of the Fast, or to buy the entire fins, so to have two pairs to use in different conditions. For example, the HD Maxx among the rocks in shallower water, and the H.Dessault Fast for deeper dives and further away from rocks. In both cases, the footpocket model would be the same to maintain the comfort to which one is used to. The Fast will be, coming from the HD Maxx, already a big step ahead in the carbon fiber fins sector, always with the very important by C4 Technology design.
