The Propulsion fin was designed in collaboration with the Italian Special Forces and has a blade manufactured out of a secret techno polymer and shoe material made from a thermoplastic rubber.According to Seac Sub, the end result is a fin with a blade that features fluid dynamic channels that collect and contain water with no dispersion. This all sounds impressive, but what does it actually mean? Simply put, the blade has been modified so that when the diver makes a fin stroke, almost all the water that comes into contact with the blade is forced backwards rather than sideways. The result is a fin that directs a diver’s energy so that it propels the diver forwards rather than being lost as water falls off the sides of the fin.
The blade also features stabilisers that reduce slicing and any resultant power loss, and it is made from a combination of both rigid and soft plastics that are designed to give thrust on both the down and return fin stroke.
When compared with our favourite single-blade fins here at the Test Centre, namely the Tusa Imprex fins, it was extremely hard to tell the difference between them. In other words, the Propulsion performs as well as one of the best fins we know. But where the Propulsion fins have the edge is on the shoe fitting and strap. The shoe’s generous height and width means that your boot sits along way into the shoe fitting rather than hanging out, and the spring-loaded straps are simply fantastic – why any manufacturer would use the old rubber straps is beyond me. The spring straps make getting the fins on and off easy, which is especially useful when shore diving or when at the back of a rolling boat. You can save yourself £25 by buying these fins minus the spring-loaded straps, but don’t – they’re a superb feature.
The Propulsion 4x4s come in a colour choice of black, red, pink, blue and yellow and in three size fittings. At £85 they’re not a steal, but definitely worth a look.
Provide plenty of thrust and feature excellent straps
Value 7 Performance 9
Blandford Sub Aqua • 01823 663849 •