Monofins are better for competitive freedivers and probably essential for winning freediving competitions or setting records in certain disciplines. They can make any diver faster and more powerful in the water. This major advantage may be offset by the disadvantages in terms of greater difficulty of use compared to bifins, and lack of maneuverability in the water. Recreational freedivers and spear fishers may prefer to use bifins.
A monofin is better for diving deeply in a straight line as fast as possible, and is therefore the preferred choice of elite and professional freedivers in several competitive freediving disciplines. Using a monofin can increase the power and speed of any diver. Bifins may still be a better choice for recreational divers, freediving buddies or those who struggle to master dolphin kick swimming.
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If you’ve ever watched an elite freediving competition you may have noticed that the vast majority of competitors choose to wear a monofin rather than flippers (bifins). If you want to understand why, then this article is for you. We tell you more about the characteristics of monofins and advantages of monofin freediving as well as some of the downsides and disadvantages you might want to consider.
Is a monofin faster than flippers?
When chosen well and used correctly, a monofin gives significantly better performance for power and speed than flippers / bifins. This can make a major difference for long and deep freediving. Most freedivers will find that monofins are both faster and more efficient in terms of energy use for straight-line freediving. This makes them the best choice for several competitive freediving disciplines or setting records in these areas.
How do I choose a monofin for freediving?
Before buying a monofin for freediving, it’s best to do some research, and ideally borrow some different types of monofins from other freedivers to work out what suits you best in terms of material (e.g. fiberglass, plastic, carbon fiber, carbon composite) blade stiffness, blade angle, foot pocket construction.
Personal comfort and how the fin will be used are both important in choosing a monofin. Recreational and competitive freedivers may have very different requirements, as will people of different sizes and levels of experience.
A basic monofin design consists of foot pockets attached to a single finning blade of wide diameter. Materials, construction and components can vary widely. Some monofins are longer or stiffer than others and may be better suited to divers who are bigger, stronger or more experienced. These will require more strength and better style to maneuver correctly for maximum performance.
If you’re starting out with monofins, it may be better to begin with a cheaper, softer blade while you’re working to master monofin techniques. In general, softer blades are easier to move through the water. Softer fins are therefore often used for dynamic apnea or long surface swims. Stiffer fins will give more power and speed to movement through the water but they also require greater physical strength.
Do you need a monofin?
As a recreational diver, you will not need a monofin. It is probably safer and more enjoyable to begin freediving without one. If you are a more experienced freediver you might find it interesting to try a monofin and see whether you enjoy using it and how it otherwise affects your freediving experience and performance.
Bifins / flippers may not be as fast as monofins but they are more comfortable to wear, easier to use, and more maneuverable in the water. This can make them a better choice for recreational freediving or spearfishing, where a diver may be stopping or turning frequently in the water, rather than solely focusing on depth and timing.
Monofins do dominate freediving at elite and professional level and almost all fin-discipline freediving records have been set with monofins. If your aim is to take part in certain disciplines at freediving competitions, or attempt freediving to record depths, you will need a monofin to have a realistic chance of succeeding.
Many freedivers also prefer to dive without any fins, monfin or bifin, preferring the physical and mental freedom of having less equipment on their bodies.
What are monofins good for?
Monofins are good for professional or elite freediver aiming to increase their dive time, distance or depth. Disciplines in which monofins are particularly widely used include:
Dynamic apnea with fins (DYN) – this involves swimming as fast or as long as possible in a straight line close to the surface, without any need for high maneuverability.
Constant weight freediving (CWT) – constant weight divers descend down to a declared depth on a single breath without varying weight. Using a monofin at the depths which elite freedivers can reach in CVW gives more force to counteract both positive and negative buoyancy.
Variable weight diving (VWT) – variable weight divers also descend down to a declared depth on a single breath but this time with the assistance of additional weight which can then be discarded for the ascent.
Having considered areas where monofins are the right choice, there are also some freediving areas and activities where a monofin is definitely not the best option.
Recreational freediving – someone spearfishing, or combining freediving and snorkeling around a reef, wreck or other underwater feature, will probably prefer the greater ease of movement provided by bifins, which allow them to change direction quickly rather than only go in a straight line. With hands above the head, taking photographs is not possible. It’s also nearly impossible to tread water in one spot when wearing a monofin.
Acting as diving buddy – if you’re someone’s freediving buddy and an emergency occurs, you will find rescuing and towing another diver far easier if wearing bifins.
Equalizing ear pressure using hands: the dolphin kicking technique involves holding the hands above the head constantly. This means that you will need to master techniques and accessories for equalizing the pressure in your ears hands-free. If you cannot find a way to do this, then monofinning may not be for you.
Added to these considerations, monofins are more expensive than bifins, trickier to transport, and harder to put on. At the same time, learning dolphin kicking is harder than learning to dive with bifins and some people will require the assistance of a professional coach or trainer.
Deciding whether to buy a monofin or bifins is not as simple a decision to make as you might think if considering only speed and power during the dive.
How fast is a monofin?
The Lunocet monofin can apparently enable swimming speeds of around 13 km/h over a distance of 50m.
In general, the speed at which you can move with a monofin is proportional to the speed that you can move without it. With correct use, everyone’s speed can be boosted with a monofin but this will be in relation to your existing capability.
Monofins can reportedly enable an extra 15-50% more distance in movement for the same effort, compared to wearing bifins. Almost any freediver can add around 10m+ to their straight line dive depth simply by using a monofin.
Monofins increase speed by several means, including forcing the body to adopt a more hydrodynamic shape and more efficient swimming techniques (dolphin kicking), as well forcing more water out of the way with its wider blades.
The dolphin kicking style can also relax the diaphragm muscles for improved breath-holding, and boost stamina by spreading effort over more muscle groups and warding off lactic acid build-up. Both of these can support diving speed and depth further.
How do you use a monofin?
The first thing you will need to learn is how to put on a monofin, a process which can be more challenging than putting on bifins and may require some practice, trial and error.
If you’re swimming out from shore (rather than diving off a boat) you will need to hold your monofins in one hand while swimming until you reach your diving spot, something you may not relish in high winds or strong currents
If diving from a boat, many freedivers choose to put on and take off monofins in the water and it will certainly be easier to put on the monofin if you wet inside the foot pocket first, potentially also greasing your feet with soap or a suitable lubricant.
Men with hairier feet may find it easier to get into a monofin if they shave their feet. Feet are inserted into the foot pocket one at a time, making sure that the heel strap rests on the back of the heel bone rather than over the Achilles tendon.
Once you’re in the water and in your monofin, you’ll need to think about monofin swimming and diving technique which is based on dolphin kicking and may be significantly different to what you use when wearing flippers / bifins.
Classic monofin technique aims to keep the body as streamlined as possible while diving, extending the arms and hands behind the head and close together, with the chin tucked into the chest. Hands and arms should form a straight unbroken line with the back. Movement should come from your sternum and ripple down the body
While highly efficient, this style of movement can be hard to achieve and may feel uncomfortable to begin with. Most newcomers to monofinning will automatically try to propel themselves by bending the knees and frog-kicking and will find it particularly difficult to keep the the legs straight. Training to use a monofin can take a long time for some people.
When you begin using a monofin you might choose to try it only for short periods so that you can gradually build up strength and flexibility, while avoiding cramp.