THERE ARE SO MANY FINS now available on the market that even those of us in the trade can be deceived into thinking that one type is very much like another.
Its only when you get them side by side that you can see the differences, but how do you know which are the more effective
Pete McCarthy, the man who patented the Natures Wing split fin design, kindly made DIVER some underwater speedometers, with the intention of proving that his fins were best. We still have them, and are not so precious as to resist using them to get a definitive performance value for any fin we choose to use, split or not.
But surely fins are not just about speed, are they We want to measure the efficiency of the fins in moving a diver forward.
Well, if you can get a speed of two knots in still water, you will accomplish a speed of three knots over the ground with a one-knot current behind you.
Conversely, if you head into a one-knot current you will achieve only one knot over the ground. Ask any ships navigator.
So we believe that these speedometers, used in controlled circumstances in still water of a fixed depth, give a good indication of the efficiency of any fin when compared with another.
Naturally, test divers have to be well rested between swims so that the exercise is non-aerobic, and we have to be confident that we are as unbiased as possible. Thats easy, because we want to know how the fins compare one to another just as much as anyone else!
The most efficient kick is contained within the radius of the slipstream of the body as it moves forward. A wider scissor-like kick is actually less efficient. This is most apparent when heading into a current.
We grouped the fins by the average results we achieved.
The blades of the fins are either split (propeller fins) or flat, or are of the channelled water-scooping variety. We have never really discovered the advantage of vents, but some manufacturers use them.

SOME SAY SPLIT FINS are no good in a current. The first to reach the market, Apollo Biofins, worked well and were very effective in the water. However, some other major manufacturers used the split-fin concept to take the effort out of finning instead of increasing efficiency. It was what the buying public wanted, they said.
These models sold well in dive stores but eventually gave split fins a bad press, because there is no such thing as a free lunch.
These rather soft and floppy versions of split fins proved poor when the chips were down, and you had to work hard swimming into an oncoming current.
Other details, such as the packing weight and the purchase price, could be very important to you. We concentrated on open-heel fins, as these are undoubtedly more popular with those who like to wear neoprene boots when diving.
Bigger sizes of fin have bigger blades. We stipulated that fins entered for this comparison should all be one size up from Regular or Medium, thus giving them all a level start.
We include the overall length for this supplied size only but such a measurement gives a good comparison with the other fins.
Why is the foot-pocket so important We like fins to have a long pocket that will encompass the wearers foot right up to the heel. This makes the fin part of the leg rather than putting strain on the ankle.
By encompassing as much foot as possible, less strain is put on the shin muscles during the downward power kick. The more support under the heel, the less tiring the fin will be over long periods of heavy finning.
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Its the forward kick that provides most of the propulsion. We measured how much of our standard boot was contained in each fin.
With one exception, recorded average speeds ranged from 3 to 4.5kmph, but it soon became apparent which fins were consistently faster.
Fins in Group A were the most efficient, but were unusual in that you needed to get used to them to get the best out of them.
Group B were generally excellent performers. Group C were not as good, whereas fins in Group D were even less so.
We reserved a special place for one pair of fins in the bottom Group E.

We often hear divers talk about manoeuvrability. Clearly longer fins are more difficult to use in confined spaces than short ones, but for frog-kicking and skulling, as opposed to conventional flutter-kicking, its a matter of getting used to the fins you have.
Most fins are now supplied with rubber straps and standard quick-release buckles in the form of pinch-clips. The exception are those from Mares, which come with an advanced buckle system (ABS). This allows the user to cantilever them tightly onto the foot rather than trying to physically pull the straps tighter. All fins can have their straps substituted for stainless-steel coil-spring straps to keep the foot tightly in place without adjustment.
Finally, whatever the performance, if fins are not comfortable for you, youll never be happy with them. However, we offer the results of our comparison test as a starting point in your quest for the perfect open-heel fin.
All the fins had similar straps and buckles save for the Mares (ABS) and Force (simple elastic bungee), and are made in Italy unless otherwise stated.

TUSA REEF TOURER (E) £19
width=100% COLOURS 2
SIZES S, M, L
DRY WEIGHT 1.0kg
OVERALL LENGTH 34cm
FOOT POCKET 17cm long
SPEED 2.7kmph
www.cpspartnership.com
Tiny fins in a very soft rubber that have foot-pockets equally suitable for unclad feet as for boots, we were surprised that these performed well at all. They are obviously intended for backpacking snorkellers. That said, we gave them a go and found they were a lot better than no fins at all. They are made in Taiwan.

COLTRI-SUB KRISTAL (C) £22
width=100% COLOUR 2
SIZES S/M, M/L, L/XL
DRY WEIGHT 1.7kg
OVERALL LENGTH 64cm
FOOT POCKET 27cm long
SPEED 3.4kmph
www.coltrisub.it
A long slim fin with a foot-pocket that looks narrower than it is. A wide soft centre channel takes care of the scooping effect that pushes the diver forward. The side-rails of the blades are quite skinny towards the business end, leaving less return to the flick than with some other fins. The fins suck onto the boot better than we would have liked when the time came to pull them off.

COLTRI-SUB NEPTUNE (D) £22
width=100% COLOURS 1
SIZES S/M, M/L, L/XL
DRY WEIGHT 1.7kg
OVERALL LENGTH 60cm
FOOT POCKET 26cm long
SPEED 3.3kmph
www.coltrisub.it
They may be black and of a conventional jetfin type of design, but dont be fooled. Theyre made with lightweight technopolymer. They take a wide boot if only just past the instep, and they work, even though they use the most basic paddle fin design in an economically-made form. Its the sort of fin you might buy when first getting equipped.

IST BORA BORA (C) £30
width=100% COLOURS 1
SIZE8 M, L, XL
DRY WEIGHT 2.8kg
OVERALL LENGTH 68cm
FOOT POCKET 22cm long
SPEED 3.5kmph
www.sea-sea.com
Are these split fins without the split The long blades are in two sections joined
by a deep-V flexible rubber panel for a central channel. Strong side-rails give support. The blade is nicely integrated with the wide foot-pocket, which was spoiled only by being too shallow at the toe end to get a boot properly inserted all the way. Taiwanese-made.

BEAVER VELOCITY (D) £37
width=100% COLOURS 4
SIZES S/M, M/L
DRY WEIGHT 1.8kg
OVERALL LENGTH 60cm
FOOT POCKET 23cm long
SPEED 3.3kmph
www.beaversports.co.uk
Whats in a name Not speed, in this case. However these fins are remarkably cheap and they work, so if the purchase price is important, you wouldnt go far wrong in buying them. With a flat, almost rigid blade smoothly integrated with a small foot-pocket, their uniqueness is in their simplicity and economy rather than their efficacy when it comes to putting your best fin forward.

BEAVER ASSAULT (D) £39
width=100% COLOURS 1
SIZES M, L, XL
DRY WEIGHT 3.3kg
OVERALL LENGTH 53cm
FOOT POCKET 29cm long
SPEED 3.1kmph
www.beaversports.co.uk
These vented fins are short, heavy and made from a traditional black rubber compound. They seem perfect for wreckers and those who walk about on dives, with a descent and ascent and not much horizontal finning in between. A remarkably wide foot-pocket takes the chunkiest drysuit wellie. They are full of military cred for wannabe SBS members but not for those who wants to cover large distances. By far the heaviest fins reviewed here, they are made in Taiwan.

OCEANIC VIPER (C) £40
width=100% COLOURS 4
SIZES S, R, XL
DRY WEIGHT 1.6kg
OVERALL LENGTH 64cm
FOOT POCKET 29cm long
SPEED 3.6kmph
www.oceanicuk.com
This is a conventional scooping fin design with a broad channelling effect afforded by a large V-shaped soft area in the centre of the blade. Its light weight will make it appeal to those who pack to travel, and this was reflected in the test divers abilities to accelerate with it quickly. The otherwise generous foot pocket could have been improved with more space at the toe end. These fins are made in China.

AQUALUNG CARAVELLE (C) £47
width=100% COLOURS 3
SIZES S, R, XL
DRY WEIGHT 1.9kg
OVERALL LENGTH 66cm
FOOT POCKET 29cm long
SPEED 3.4kmph
www.aqualung.com/uk
With a blade that is almost completely flat across its entire width, this fin design suits those with strong ankles and the ability to keep the blade square on to the kick. The inside of the foot-pocket is entirely smooth, making the fin suck onto the boot and sometimes prove difficult to pull off.

CRESSI RONDINE A (B) £47
width=100% COLOURS 3
SIZES XS/S, S/M, M/L, L/XL
DRY WEIGHT 2.2kg
OVERALL LENGTH 65cm
FOOT POCKET 30cm long
SPEED 4.1kmph
www.cressi-sub.net
These good-looking fins have a flat blade with a variable thickness to ensure a uniform degree of flex. They take their name from the super-long Rondine free-diving fins that have dominated the world of competitive spear-fishing. However, these are short enough to pack in a bag, but you will still need to be fit in the heart and legs department to get the real advantage from them. A long foot-pocket ensures that you make the most of your muscle power.

MARES AVANTI SUPERCHANNEL (A) £50
width=100% COLOURS 4
SIZES S, R, XL
DRY WEIGHT 2.3kg
OVERALL LENGTH 62cm
FOOT POCKET 28cm long
SPEED 4.2kmph
www.mares.com
A massive central flexible channel augmented by two similar smaller side channels gives this paddle fin a full scooping effect. They are a direct development of the successful Avanti Quattro. Its a pity that the manufacturer has chosen to make the foot-pocket a little shorter, resulting in more strain on the shin muscles. Made in the Czech Republic at the time of writing, it uses Mares ABS buckles.

EFFESUB POWER 5 (B) £50
width=100% COLOURS 4
SIZES S, M, L, XL, XXL
DRY WEIGHT 1.6kg
OVERALL LENGTH 64cm
FOOT POCKET 30cm long
SPEED 4.0kmph
www.blandfordsubaqua.co.uk
These fins are very light and look a bit cheap and flimsy at first glance, but appearances can be deceiving. In the water they were stonkingly good. The blade looks uncomplicated and fairly rigid but it is well integrated with a part-rigid foot-pocket that supports the foot right up to the heel. This gives very effective forward kicking without strain.

OCEANIC VORTEX V8 (B) £53
width=100% COLOURS 4
SIZES S, M, L, XL
DRY WEIGHT 1.9kg
OVERALL LENGTH 64cm
FOOT POCKET 30cm long
SPEED 3.9kmph
www.oceanicuk.com
Similar but different to the V16, this fin has a more accommodating if narrower foot-pocket with all the advantages entailed, but it proved hard to pull the boot out after in-water use because of the totally smooth inner surface and very difficult to get our drysuit boots into. With a flatter blade, it appears to be made from simpler materials than the V16, and this is reflected in the weight and the price.

SEAC SUB MANTA (D) £59
width=100% COLOURS 3
SIZES XS, S, M, L
DRY WEIGHT 1.6kg
OVERALL LENGTH 68cm
FOOT POCKET 30cm long
SPEED 3.1kmph
www.beaversports.co.uk
A prizewinner for least weight, with nothing more than what looks like a slab of flat rippled plastic attached to a foot-pocket, these fins make no concessions to the science of scooping or channelling or fish-tailing. The foot-pocket, though not wide, is long and makes the most of the users efforts, but it takes concentration to keep the blades presented to the water for best effect. Its an old model that we believe we will not be seeing so much of in the future.

CRESSI REACTION (A) £63
width=100% COLOURS 3
SIZES XS/S, S/M, M/L, L/XL
DRY WEIGHT 2.3kg
OVERALL LENGTH 69cm
FOOT POCKET 30cm long
SPEED 4.2kmph
www.cressi-sub.net
With a massive flat blade tilted the opposing way from the foot-pocket to that of most other fins, these are fins for divers with the muscle power to use them. Big flat blades, sharp enough to cut through butter, need to be presented firmly to the water without any twisting to get the best out of them, but the long foot-pocket ensures that the fin becomes an integral part of the leg. These fins are for the more athletic amongst us.

AQUALUNG BLADES FLEX2 (C) £66
width=100% COLOURS 3
SIZES S, M, L
DRY WEIGHT 2.3kg
OVERALL LENGTH 67cm
FOOT POCKET 29cm long
SPEED 3.4kmph
www.aqualung.com/uk
An old-fashioned-looking fin that has a foot-pocket that gives generous support to the ankles via the heels, and a massive area of finely grooved blade that is supported from flexing too much by integrated rails. Its a shovel of a fin. There is a unique clip on the strap that undoes easily and makes stepping out of the fin simple, although it did tend to come unfastened during the test.

TUSA TRI-EX SF-6 (C) £67
width=100% COLOURS 7
SIZES XS, S, M, L, XL
DRY WEIGHT 1.7kg
OVERALL LENGTH 63cm
FOOT POCKET 26cm long
SPEED 3.3kmph
www.cpspartnership.com
More suited to a dainty Far Eastern foot by the narrowness of the foot-pocket, nevertheless these Taiwanese-made fins performed well with a very conventional flat blade that has hardly any flex, and therefore no scooping or channelling effect whatsoever. Strong side-rails effect a strong dip away from the line of the foot, and if you find them comfortable for your feet, youll enjoy using them.

MARES AVANTI QUATTRO (A) £70
width=100% COLOURS 4
SIZES S, R, XL
DRY WEIGHT 2.3kg
OVERALL LENGTH 64cm
FOOT POCKET 29cm long
SPEED 4.3kmph
www.mares.com
The patent must be running out on this four-channel paddle-fin design soon, so Mares will be aiming to replace it with something better. Thats tough, because these are the fins by which others have been judged - and remain excellent. The boot is accommodated in the foot-pocket right up to the heel in the original Italian-made version. This is the Czech-produced version but production will soon return to Italy. Mares ABS buckles.

SHERWOOD KINESIS EX (C) £70
width=100% COLOURS 2
SIZES S, R, XL
DRY WEIGHT 1.8kg
OVERALL LENGTH 63cm
FOOT POCKET 22cm long
SPEED 3.6kmph
www.sea-sea.com
Reminiscent of the older Mares Volo or Dacor Tiger, this is a pivoting fin design that gives as little stress to the muscles as possible but at the same time is less effective in producing results. We note that Mares later upped the ante with the impressive Volo Power, but the results we got from the Kinesis Ex were rather a flop by comparison. On the upside, it is one of the most lightweight fins tested, and if you are travelling to where the diving is easy, why not use them

IST TALARIA (B) £75
width=100% COLOURS 1
SIZES M, L, XL
DRY WEIGHT 2.6kg
OVERALL LENGTH 60cm
FOOT POCKET 29cm long
SPEED 4.1kmph
www.sea-sea.com
This is a nice looking split fin with a purposeful dip to the soft floppy blades, each supported by strong side rails. Very similar in shape to the Xpert Zoom Taiwanese-made fins, these are made from a different, more rubber-like, compound. The foot-pocket is big enough to accommodate the widest drysuit boot and, available in a serious all-black colour scheme, these fins should find favour at British dive sites.

SCUBAPRO TWIN SPEED (B) £85
width=100% COLOURS 3
SIZES S/M, M/L, L/XL
DRY WEIGHT 2.4kg
OVERALL LENGTH 70cm
FOOT POCKET 28cm long
SPEED 4.0kmph
www.scubapro.com
Not the sort of fins you want to try putting on in a crowded inflatable boat, the long and skinny blades seem to go on forever, supported by their medium-weight side-rails. It didnt help that the foot-pocket was so narrow that we ended up with them dangling at the end of our toes. Only the daintiest of drysuit divers will make use of these, and thats if they buy a size bigger than they would otherwise have expected.

OCEANIC VORTEX V16 (B) £95
width=100% COLOURS 4
SIZES S, R, XL
DRY WEIGHT 2.1kg
OVERALL LENGTH 63cm
FOOT POCKET 24cm long
SPEED 4.0kmph
www.oceanicuk.com
This compact fin has an attractive looking design with very little flexibility, except for that provided by the split in the curved-down blade. The foot-pocket looked generous until we tried to get our standard boot into it, when it became apparent that it was quite short. We thought the strong performance of the fin belied its appearance, though at the expense of some calf strain.

TUSA XPERT ZOOM SF-8 (B) £98
width=100% COLOURS 5
SIZES S, M, L
DRY WEIGHT 2.4kg
OVERALL LENGTH 62cm
FOOT POCKET 28cm long
SPEED 4.0kmph
www.cpspartnership.com
A design that seems to have been closely copied by one or two other manufacturers since it was introduced, the fairly rigid split blade of these Taiwanese-made fins dips sharply away from the line of the foot and is supported by strong side-rails. We would have preferred a longer foot-pocket to allow us a stronger kick but these fins still performed up there with the best.

MARES RAPTOR (A) £100
width=100% COLOURS 4
SIZES S, R, XL
DRY WEIGHT 2.8kg
OVERALL LENGTH 62cm
FOOT POCKET 24cm long
SPEED 4.5kmph
www.mares.com
Mares always said it wouldnt make split fins, but it has, and jolly good they are too. The blade is smoothly integrated with the foot-pocket for minimum disruption of the water flow. It was a pity that the foot-pocket was a little short, because this put unnecessary strain on shin muscles. The blade either side of the split is quite rigid, and supported by strong side-rails. Mares ABS buckles.

TECHNISUB SLINGSHOT (A) £100
width=100% COLOURS 3
SIZES S, R, XL
DRY WEIGHT 2.7kg
OVERALL LENGTH 69cm
FOOT POCKET 31cm long
SPEED 4.3kmph
www.aqualung.com/uk
With blades almost big enough to body-board with, these new super high-tech fins get their elasticity from inbuilt silicone springs rather than the flexibility of the hingeing blade itself. The springs can be adjusted during a dive to produce a greater or lesser flick effect.
A foot-pocket accommodates the entire boot up to the heel, thus making the fin part of the leg.

APOLLO BIOFIN PRO XT (A) £115
width=100% COLOURS 1
SIZES S, M, L, XL
DRY WEIGHT 3.0kg
OVERALL LENGTH 57cm
FOOT POCKET 24cm long
SPEED 4.4kmph
www.bluesports.co.uk
The Japanese Apollo company was the first to run with the Natures Wing split-fin idea, and this XT version of the heavy-weight all-rubber Biofin is more resilient to deformation during finning, and therefore that much more effective. The footpocket of each fin is a bit short for those with long feet, but the results against the speedometer are undeniable. We suggest that you get them with the more expensive stainless-steel fin-strap option.

SCUBAPRO TWIN JET (C) £119
width=100% COLOURS 1
SIZES S/M, M/L, L/XL
DRY WEIGHT 2.7kg
OVERALL LENGTH 63cm
FOOT POCKET 31cm long
SPEED 3.4kmph
www.scubapro.com
When these US-made fins were introduced, they took the market by storm because they proved so comfortable. Alas, they were so floppy that they were useless in a current and gave split fins a bad name. This latest version seems to be constructed from a different and more resilient material and has a heel support that makes the most of the forward kick, but it was still not as good as we hoped when it came to producing results.

SCUBAPRO TWIN JET MAX (A) £139
width=100% COLOURS 3
SIZES S, M, L, XL
DRY WEIGHT 2.8kg
OVERALL LENGTH 67cm
FOOT POCKET 30cm long
SPEED 4.4kmph
www.scubapro.com
Not to be confused with any Scubapro fin with a similar name, this split fin gives the lie to the idea that they are no good in an oncoming current. Twin Jet Max fins are massively built and have a vented area between the foot-pocket and the blade, which has strong side-rails and rigid panels. They have one of the most generous foot-pockets on the market for length, width and depth, and are intended for those with serious amounts of finning to do.

FORCE FIN EXCELLERATORS (A) £350
width=100% COLOURS 6
SIZES L, XL, XXL
DRY WEIGHT 2.0kg
OVERALL LENGTH 50cm
FOOT POCKET n/a
SPEED 4.5kmph
www.forcefin.com
Unconventional, compact and with a moulded stirrup instead of a foot-pocket, these Californian-made fins demonstrate that you dont necessarily need a large blade area to shift water. The whiskers atop the blade are instantly adjustable for varying the thrust. These fins require a rapid flutter-kick to be effective. Made from very tough last-forever polyurethane, the price says it all. You will either love them or hate them.