Fins are designed for different water activities, so to achieve the best performance when you freedive, it is crucial to find the right freediving fins. If you are a beginner freediver, you might need some help to decide if bi-fins or monofins, plastic, fiberglass or carbon models are the best. This part of our freedive equipment guide explains how to choose the best-fitting fins!
Types of freediving fins
All freedive gear manufacturers offer a wide range from beginner freediving fins to high-end products. You can choose bi-fins with fixed or changeable blades, as well as monofins.
Fixed blade fins
Freedive entry-level fins are bi-fins with fixed blade when the blades are attached to the foot pockets. These fixed thermoplastic blades are great as entry-level freediving fins. They are inexpensive, durable, but as you progress, you might find them stiff and not so reactive.
- high-performance fins made of 3 different materials
- reactivity and lightness
- anatomical foot pocket for the best fit
- comfortable with and without socks too
Fins with changeable blades
Advanced freedivers use freediving fins with changeable blades (also called modular freedive fins) due to performance and practical reasons. From both aspects, it is a good idea to buy modular freediving fins because you can start with the cheaper, less-reactive plastic blades then upgrade to more powerful fiberglass or even carbon as you progress.
Another advantage of modular bi-fins is that you can buy the foot pockets and blades separately. Like this, if you find a foot pocket comfortable from one brand but blades prefer from another or vice versa, you can freely match them. Most commercial foot pockets and blades are compatible, but always double check with the manufacturer before purchasing.
- infusion technology carbon fiber blades
- extremely comfortable thermo rubber foot pockets
- maximum power - less effort when descending/ascending
- interchangeable blades are available in 3 stiffness
One more important thing, it is a lot easier to travel with removable blade fins! Since freedive fins are long (total length varies between 80-105 cm with foot pockets) it is difficult to transport them. Modular fins can be easily dismantled for traveling. To protect your fins while storing and land transport, keep them in freedive fins bag!
Last but not least, talk about monofins too! Monofins are designed to achieve maximum output with minimum effort. These type of fins are used mainly while pool training and on competitions in CWT, constant weight discipline. They are not so effective for fun freediving since it is difficult to change direction or move around with them, however, a monofin training could significantly develop your finning skills.
Learning the dolphin kick is the most important movement in swimming that helps a lot to significantly improve your freediving technic too. The best way to master this technic is training with monofins. A comprehensive monofin training helps you to develop powerful kicking that generates from the hips and not from the knees. It is a great workout for the abs, lower back, quads and glutes, increases the flexibility the feet and ankles, improves body balance and strengthens core muscles.
- extremely reactive finswimmer monofins
- 7 degrees foot pocket-blade angle for powerful kicks
- top quality multilayered fiberglass material
- soft rubber foot pockets, free neoprene socks
Plastic, fiberglass or carbon freediving fins to buy
Entry-level freedivers typically start with plastic blade fins that are cheap and durable. Interchangeable blades are available in plastic, fiberglass and carbon. To figure out which one will suit you the most, go through on the features and advantages of the different types.
- Freediving fins with plastic blades
Recommended for entry and intermediate level freediver
Pros: durability and low price
Cons: less effective, in cold water can get rigid
- Fiberglass freediving fins
popular choice by advanced freedivers and spearfishermen
Pros: high performance and effectiveness
Cons: get easily scratched
- Carbon freedive fins
used mainly by professionals on competitions
Pros: top effectiveness, highest performance
Cons: fragile, high price
Fiberglass and carbon freedive fins are cool and effective, but if you just started freediving, you don’t necessarily need them. Fiberglass composite blades are the most commonly used by advanced freedivers. These offer the best value for money ratio: they are efficient and ensure great power transfer.
Our experience is, that plastic blades sometimes feel rigid, not effective especially while swimming on the surface, therefore they can be tiring for the legs in the long run. The Leaderfins Fiberglass Fins are a good choice, swimming on the surface is easy with them and underwater finning is also effective!
How to choose blade stiffness?
Almost all manufacturers offering their blades with 3 different stiffness: soft, medium and hard. The stiffness you need depends on your body type and it is also important what type of diving you do.
Entry-level freediving fins usually come with soft or medium plastic blades. When buying composite or carbon blades, in most cases you will be asked to choose what stiffness you want. Don’t start with hard blades if your legs are not strong enough, because you will suffer and burn too much oxygen.
- pure carbon (100% carbon fiber+epoxy resin) blades
- 20 degrees angle for best performance
- rubber side rails for maximum efficiency
- soft, medium and hard stiffness
If you have a bigger body and/or strong legs go for hard blades. The bigger you are the stiffer blade you need in order to push your body mass through the water. If they are too soft to your body, finning will be easy but not effective.
While freediving in currents, wavy conditions, stiffer blades work better. If you do easy, shallow dives and your goal is to get close to marine life and observe them, better to have softer blades that cause less vibration underwater (fish and sea creatures communicate mainly with vibrations and sounds). For deep diving, you need harder blades.
How to find the best fitting freediving fins?
Freedive fins come with closed heel foot pocket design for the best power transfer. Technically your fins work as the extension of your legs, so your foot pockets have to fit properly. The better the fit, the more efficient your kicks are.
If they are a bit lose, wear them with thicker neoprene socks or use fin keepers for the perfect fit. Quality foot pockets made of a thermo-rubber mix. They are softer around the ankle and toes for maximum comfort, but reinforced where needed for increased energy transfer.
To find the best fitting freedive foot pockets, do a research before your purchase which one is recommended for your foot-type: some are designed for wide foot but there are narrow feet freediving fins too. Regarding sizing, the experience shows that in most cases you can order your actual shoe size and still you will be able to wear the fins with 2-3mm thick neoprene socks. At some models, the foot pockets tend to go big/small, but in these cases, usually you will find a hint from the manufacturer or from other freedivers.
More freediving gear buying guides:
- What type of snorkel to buy for freediving
- Why use rubber weight belt for freediving
- Freediving computer buying tips
- How to choose wetsuit for freediving
- Freediving mask guide
AG is a certified diver and freediver who started to explore the underwater world in 2005. He enjoys sharing his experience of the best freediving destinations and equipment tips as well.
"Disclosure: This article may contain affiliate links. If you decide to make a purchase, I'll make a small commission at no extra cost to you."