Find out why the Alchemy V3-30 freediving fins are at the top of our favourite equipment list! 

  • 15 layers of carbon fibre for strength and durability
  • Laboratory tested for maximum hydrodynamic efficiency
  • 33 degree total effective angle for a streamlined performance
  • Bi-axial weave pattern of carbon fibres for reinforcement
  • The foot-pocket must be properly sized and fit snug
  • Ensure the stiffness chosen is suitable for activity and experience

The environment

Waterton Lakes National Park, Canada

We tested Alchemy’s V3-30 carbon fibre freediving fins with the C4 “300” foot-pockets. Our testing ground was quite unusual to most freedivers: a Canadian glacial lake. Water temperatures at less than 6C degrees with strong thermoclines. In these conditions, a 7mm thick wetsuit is required for cold water freediving.

Unfortunately, all this neoprene creates strong positive buoyancy. Therefore, a comfortable and powerful freediving fin is required for energy conservation in the first 20 meters. We put the Alchemy’s V3-30 to the test on propulsion and power output in these conditions. They are difficult freediving conditions, so ideal to test one of the top carbon freediving fins on the market.

Cold water freediving tests

We tested the following type of carbon freediving fins from Alchemy:

  • Model: V3-30
  • Color: Red with White Water Rails
  • Stiffness level: Medium/Soft
  • Footpocket Type & Size: C4-300 (White) & 40/41 EU

At 800mm long and 195mm wide, we found these dimensions to be ideal. Enough length to generate power, but not so long as to create too much drag. Suitable for Constant Weight (CWT-B) competition dives or deep spearfishing.

Choosing the correct stiffness is very important to finding the right fin for you. Furthermore, the foot-pockets must to be sized correctly to ensure a snug fit.

Keep reading to find out the details you must know before buying a pair!

The carbon blades

Bi-axial weave pattern

This is a detailed design feature that makes Alchemy freediving fins stand out from other competitors. Also known as a satin weave, Alchemy designs using the bi-axial weave. Alchemy blades are created with fifteen layers of weaved carbon fibre. Furthermore, the axis of the layers of carbon are rotated fourteen times.

What does this mean?

This feature promotes a more durable blade, less likely to split and break along a singular axis. We’ve seen cheaper carbon fibre blade designs where the fibre layers have the same orientation. This design increases the likelihood of breaking and crack propagation.

The Vacuum Assisted Resin Transfer Moulding (VRTM) process Alchemy uses is at the top of its game. This manufacturing design helps to create a “near air void free” layout within the carbon fibre structure. With 45 tons of “total pressure” applied (i.e. P = F/A), the void ratio is highly reduced and resin voids are reduced as much as possible. This allows Alchemy to boast an impressive carbon fibre content of greater than 72%!

The hard-tip

The hard-tip that Alchemy employs in its design is a unique patented feature for carbon fins. The tip of the fin is stiffer relative to overall blade stiffness. This doesn’t create more resistance, but rather enhances the oscillating movement of the flexible foil in water.

As a flexible foil, the blades bend in one direction, only to quickly bend in the other direction. This mechanism creates forward thrust and provides propulsion. This flexible foil, or the blade, thus oscillates back and forward.

By designing a hard-tip with greater stiffness relative to the blade, you can better control the oscillating motion of the blade. This allows you to avoid stalling the blade, so you won’t waste any oxygen.

Here’s some trivia for you; Skyscrapers use a similar concept known as “Tuned Mass Damper” (TMD). A heavy weight (usually concrete or steel) is mounted at the very top of the building. It’s usually isolated from the structure by the use of springs, pendulums or water. Earthquakes will cause the building to sway or oscillate in ways that can damage the structure. This heavy weight helps to “dampen” the oscillations of the building produced during an earthquake.

In other words, it controls how the building will sway back and forth. We believe the hard-tip design plays a similar role in the V3-30 freediving fins.

Other blade features we love

The blade end that Alchemy designs for its V3-30 freediving fins is the dolphin tail shape. Based on fluid dynamics testing, this shape is considered one of the best for hydrodynamic efficiency. We also think that this shape could potentially help to reduce drag and turbulence at the end of the blade.

Alchemy saved no expense on designing and testing the most efficient design of water rails. We like these water rails a bit better than those of the previously reviewed C4 Mustang Carbon Fins. These silicone water rails are tested using a fluid dynamics software. These tests ensure the the fluid retains laminar flow and reduces the turbulence. The rails retain their shape even under extreme bending. They have a low profile and ensure hydrodynamic flow over the blade.

The V3-30 freediving fins are designed with an offset angle of 30 degrees. Additionally the footpockets are have their own internal angle of 3 degrees. This combines for a total effective angle of 33 degrees. This shape provides more leverage and better propulsion. It also allows the diver to be more streamlined in the freefall.

The Footpockets

How they fit

This is where you’ll hear many freedivers swear the first few times they put the fins on. The footpockets are tricky. There’s a reason why Alchemy sells them with a shoe horn. You will also likely have to lube them (i.e. bio-degradable conditioner) or use silicone grease. We suggest you use the most environmentally conscious option if possible.

Once they’re finally on, you will be happy at how well they fit and how comfortable they are. The footpockets remain comfortable after hours of wear. They cause minimal cramping if you’re wearing the correct size. Like most freediving fins, the footpockets run small. I usually wear 42 Euro and chose the 40-41 Euro size for these fns. The fit must be snug, but comfortable.

The footpockets are made of a highly resistant material. C4 claims it is seven times stronger than regular rubber used in most footpockets. At 316 grams, they are some of the lightest footpockets on the market. You truly feel like you’re wearing nothing.

In cold water

Our cold water suggestion is similar for wearing a monofin as described in a previous article. We recommend you buy 5-6mm socks. Cut off the tips (at the toes) and put them on your feet prior to wearing the fins. Once your fins are on, simply pull them over the heel and cover the foot-pocket. This technique will allow you to wear this fins in very cold water while maintaining a snug and “sock-less” fit.

Our recommendation

Our only suggestion to C4 is to add some padding around the heel. Many freedivers tape the opening (by the heel) since the sharp edge can cut into your skin. After a long session of deep dives in cold water, you can feel some bruising by your heel. This won’t be as big of an issue in warm water because the rubber will be a bit more flexible. However, in cold water this can quite unpleasant, especially if you’re training multiple days in a row.

Technical details about the V3-30

  • Manufacturing process: VRTM
  • 15 Carbon fiber layers
  • 14 axis of reinforcement
  • Carbon fiber content: ≥72%
  • Total length of the blade is 800 mm
  • The blade’s total width is 195 mm
  • Blade’s angle: 30°
  • Angle type: Radius
  • Warranty period: 5 (five) years from the day of manufacturing

Source: The Freedive Wire



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