Can beginners use the Molchanovs SPORT?

They can, but we would not recommend it as a first fin. The SPORT pairs a silicone foot pocket with a separate fibreglass or carbon blade, and that stiffer blade is less forgiving — it can tire out your legs quickly if your technique is still developing. Start with the CORE, build your kick, and move up to the SPORT when you are ready.

Are Molchanovs bifins better than monofins?

They are different tools. Bifins are more versatile — you can walk in them, kick in any direction, and they work well for both pool and depth. Monofins are more efficient for straight-line speed and depth but require dedicated technique. Most freedivers end up owning both and using them for different purposes.

How long do Molchanovs fins last?

With proper care, several years of regular use. The CORE is full silicone, which is highly durable and resistant to UV, chlorine, and salt water. The SPORT uses a silicone foot pocket with a separate fibreglass or carbon blade — those blades are stiff and hard-wearing too, and because they are interchangeable you can replace just a blade rather than the whole fin if you ever need to. Rinse in fresh water, dry out of direct sun, and they will look after you for a long time.

Do I need fin socks with Molchanovs fins?

Most people do not. The silicone foot pocket is soft enough to wear barefoot without discomfort. Some divers prefer thin neoprene socks for warmth in cooler water, or for a snugger fit if they are between sizes, but it is not necessary.

Can I swap blades on my Molchanovs fins, or upgrade from CORE to SPORT?

It depends on the line. The CORE is a one-piece, full-silicone bifin — the blade and foot pocket are moulded together, so it cannot be split or converted into a SPORT. The SPORT is the modular system: a silicone foot pocket with separate, interchangeable fibreglass or carbon blades, available in regular or short lengths. Within the SPORT line you can absolutely swap blades on the same foot pocket — that is the whole point of the modular design. To go from CORE to SPORT, though, you are moving to a complete new set, since the CORE cannot be taken apart. Happy to help you pick the right setup.

Molchanovs CORE vs SPORT Bifins — Which Should You Choose?

One of the most common questions I get from divers building their first proper kit — or upgrading from rental fins — is some version of this: "Should I get the CORE or the SPORT?" They both sit under the Molchanovs name, they're both bifins, and on a spec sheet they can look like two flavours of the same thing. They aren't. They're built on two completely different ideas, and once you understand that, the choice usually makes itself.

I'll walk you through how the two systems actually differ, who each one suits, and what you'll really pay — including the part the product pages don't add up for you. No fluff, no upselling. Just what I'd tell you across the counter.

The core difference: one-piece versus modular

This is the whole story in one sentence, so let me say it plainly.

The CORE is a one-piece, full-silicone bifin. The blade and the foot pocket are a single integral moulding — there's nothing to assemble and nothing to swap. You pick your size and colour, and that's the fin.

The SPORT is a modular system. You buy a silicone foot pocket and a separate blade, and you bolt them together yourself (it genuinely takes a few minutes). The blade is the interchangeable part: you choose the material — fibreglass or carbon — and the length — regular (long) or short. The foot pocket stays; the blade is what you upgrade later.

So the real question underneath "CORE or SPORT" is: do you want a sealed, grab-and-go fin, or a platform you can tune and upgrade over time?

Molchanovs CORE — the honest first pair

The Molchanovs CORE Silicone Bifins are the most affordable way into the range, and that single price holds for every size and colour — sizes run 36-37 through 44-45, in White, Blue, Black or Pink.

What I like about these as a starting fin is that the design isn't a compromise. The blade shape, foot pocket, arch support and open heel are all inspired by Molchanovs' CB2 Carbon. The silicone is hypoallergenic and UV-resistant and works across any water temperature, and because silicone flexes, the foot pocket happily accommodates both narrow and wide feet. The arch support and stabilising rails are there to keep your feet in the right position and nudge you toward a clean, symmetrical, straight-legged kick — which is exactly what a newer diver should be building.

Who the CORE is for

New freedivers who want one good pair that reinforces proper technique from session one.
Divers who travel light and want something durable and low-fuss — there are no parts to lose or loosen.
Anyone who wants soft, comfortable fins for pool training and shallower open-water work without thinking about stiffness ratings.

If you'd rather start with a complete freediving setup, the Molchanovs CORE Starter Pack bundles the CORE bifins together with a CORE freediving mask and a CORE freediving snorkel. All three are purpose-built for freediving rather than repurposed snorkel or scuba gear, and buying them together comes in below buying the three pieces separately. For a brand-new diver, it's the cleanest way to start.

Molchanovs SPORT — the system you grow into

The SPORT is where you go when you want to tune the fin to you. It starts with the Molchanovs SPORT Silicone Foot Pockets. These are the anatomical, flexible, hypoallergenic silicone foot pocket that every SPORT blade attaches to — open-heel straps so your foot can fully arch through the kick, arch support, and a choice of two widths: Standard for bare feet, Wide for use with socks. Sizes run 34-35 through 44-45.

One thing worth being precise about, because people get it wrong: on the SPORT, only the foot pocket is silicone. The blade is a separate composite part — fibreglass or carbon — that you choose and attach yourself. That's the modular bit.

Choosing your SPORT blade

Every SPORT blade comes in two stiffnesses — Soft or Medium — and five accent colours. Here's the line-up:

SPORT Bifins Blades 3 Fiberglass — the most affordable blade in the SPORT range. Regular (long) length. Fibreglass is forgiving and durable, and it's the most affordable way into the SPORT system. A great match for general training, teaching and fun diving.
SPORT Bifins Blades 3 Carbon — the flagship blade, and carbon commands a premium. Regular (long) length. Carbon gives you the most efficient, responsive energy return — the choice when you're chasing depth or distance and want every bit of your kick to count.
SPORT Short Bifins Blades 3 Carbon — carbon performance at a touch below the long carbon blade. Carbon, in a short length. The short blade is easier to manoeuvre and to travel with, and it's lovely for pool work, dynamic, and tighter spaces — while keeping carbon's responsiveness.

Who the SPORT is for

Divers who already know they're staying with the sport and want to invest in a fin they can upgrade rather than replace.
Anyone who wants to dial in stiffness (Soft vs Medium) and blade material to their own body and discipline.
Divers who like the idea of one foot pocket and a small quiver of blades — say a fibreglass set for training and a carbon set for performance.

What you'll actually pay

Here's the part I want to be straight about, because the SPORT is sold as separate pieces. A complete SPORT fin is the foot pockets plus a blade — so the real entry cost is meaningfully higher than the blade tag alone:

CORE Silicone Bifins: the most affordable option, complete and ready to dive.
SPORT foot pockets + Fibreglass (long) blades: the most affordable way into the SPORT system, but once you add the foot pockets it lands well above the CORE.
SPORT foot pockets + Short Carbon blades: a step up again, since carbon commands a premium over fibreglass.
SPORT foot pockets + Carbon (long) blades: the flagship pairing, and the most you'll spend of these combinations.

So there's real distance between the two systems — the CORE is a genuine first-pair price, and the SPORT is a step up that earns its keep through upgradability and the performance of a composite blade.

So which should you choose?

My honest steer:

Just starting, or want simplicity? The CORE Silicone Bifins — or the CORE Starter Pack if you still need a mask and snorkel too. You'll get a properly designed fin that builds good technique, with nothing to fuss over.
Committed and want to tune and upgrade? Build on the SPORT Silicone Foot Pockets. Start with fibreglass blades to keep cost down, or go straight to carbon for maximum efficiency — and consider the short carbon blades if travel and manoeuvrability matter to you.

There's no wrong answer here — only the fin that fits where you are in your diving. If you're still not sure between Soft and Medium, or between a Standard and Wide foot pocket, drop me a message before you order. I'd rather spend five minutes getting your fit right than have you swap something later.