The Design
When the fins had arrived for test my first thought had been that they looked quite small, yet felt solidly built and were heavier than I was expecting.
Intrigued, I pulled out my ancient US Divers Compro and newer Beuchat X-Jet fins for comparison. The TUSA fins are smaller, but weighed pretty much the same as the others.
Smaller can be good. I like small when people like Porsche do it, but it takes good design to make small perform like big, and TUSA certainly hasn’t spared the technology to make these fins deliver.
The foot-pocket of each fin is deep and long, to allow the effort of your kick to transfer away from your calves to the big muscles in your thighs and backside, and these pockets reached the heels of my size 8 feet.
Small vents at the front of each foot-pocket prevent the fins sealing themselves to your feet, making it easier to pull them off at the end of the dive.
Seen from above, the fins swoop to a narrow waist just ahead of your toes, then broaden out to the sculpted blade.
Seen from the side, they have a very shallow inverted V shape and the blades start out deep, top to bottom, then taper to become thinner toward the end of the blade.
The sides of the blades are made from relatively thick, hard material and the blades themselves are made from a high-quality polyurethane that TUSA calls PuRiMax. It says that this provides a quicker response to movement than either plastics or rubber.
The blades are vented just above the toes and also feature a series of half-a-dozen shaped ridges on the underside that TUSA calls a “vortex generator”.
There are more ridges and vanes on the upper surface, all intended to reduce water resistance and improve power delivery.
The whole blade area is angled down at 20°, which is intended to harmonise with the natural angle of your ankle-joint when you point your toes without trying too hard.
That is pretty much the natural position when you’re finning in the approved style, swinging from the hips with your knees straight.
The overall effect is to make the blade rigid near your foot, yet springy and flexible along its length to impart a flick at the end of the fin-stroke, and to make the fin slide through the water smoothly and cleanly. In turn, this channels all the force of your fin-stroke into forward motion under water.
I know, this sounds more like the aerodynamics of a racing car than a pair of fins, and I’ve never had an Allen key supplied with a diver footwear before. Or an instruction leaflet, for that matter, but TUSA HyFlex Switch fins come with both.
Being a bloke I ignored them, of course, and just took the fins diving. I did read the manual after I got back, and didn’t really think I had missed out on anything too important, but then I hadn’t needed to adjust the fin-straps, or I might have been less cheery.
The Allen key allows the blades to be removed for travel to make a more compact package. There’s a small stainless-steel screw either side of each fin, where the blade meets the foot-pocket. To disassemble, you remove the screws and pull the two pieces apart. Reassembly is equally easy, and the two parts fit tightly together.
The fin-straps are TUSA’s new Universal Bungee Strap system, adjustable for length and pre-set in the middle position. Changing the length of the straps is a simple enough job, but you’ll need to read the manual and probably need a coin to open the adjustment cover, so best make certain your new fins fit before you head out for the day.
Once set, there’s a big rubber D on the back of each strap to make them easy to pull on and take off, even when your fingers are numb with cold.

In Use
Back in the real world, all this meant that the fins were a doddle to put on, and then worked fairly well with the frog-kick I tend to use.
Because this bears no resemblance at all to conventional finning technique, I was quite pleased with the forward progress the fins allowed me to make.
I did feel that I ought to try using the fins in the way in which they were intended to be used, however, whereupon they pushed me through the water at satisfying speed. On the odd occasion that I ventured into current they were more than up to the job of powering me where I wanted to go, and I had no trouble keeping up with any of the divers around me.
Finning backwards has never been my greatest claim to fame, but I can do it when required, and could do it as well in these fins as in any others I’ve ever tried.

I did have a couple of small issues. The bottoms of the fins are hard plastic and rubber and grip the dive-deck of boats very nicely, but I found that they tended to slip on dive-ladders, so I needed to take extra care when exiting the water.
Once I rolled back off a RIB and the large D at the back of one fin-strap snagged, allowing the fin to float off and demanding a one-footed dash to retrieve it.
It happened only the once, however, so let’s not get carried away.
More important, probably, are the snazzy looks and the black, blue or yellow colour choice. Looks might not be a big part of your buying decision, but these fins stood out on the dive-deck and were easy to sort from a pile of others post-dive.

PRICE: £159
SIZES: 4 (XS, S, M, L/XL) to fit shoes size 3-14
COLOURS: Black, Black/Flash Yellow, Black/ Fishtail Blue
WEIGHT: 2kg/pair
DIMENSIONS: 60 x 20.5cm