This mermaid tail swimming fin is a silicone monofin - a single fin that both feet go into - with quick-release adjustable foot straps, made for children aged roughly 5 to 10. It comes in green, pink, blue or purple at $54.58 at Lets Party. Please read the swimming ability section below before buying; a monofin binds both legs together and that changes what a child can do in the water.

The appeal is obvious to any child who has watched a mermaid film, but the reason monofins are also used in real swim training is that they force a whole-body dolphin kick. Instead of the legs working alternately, the child has to drive from the hips and let the movement travel down through the body, which is genuinely good for core strength and body position. That is why competitive swimmers train with them. For most families it is a pool toy, and a good one, provided it is used by a child who can already swim.

Specifications

Type	Monofin - both feet in one fin
Material	Silicone
Stated size	16 x 2 x 15cm
Colours	Green, pink, blue, purple
Recommended age	5 to 10 years
Straps	Quick-release, adjustable elastic
Supervision	Constant adult supervision required

What's in the Box

Included	1 x mermaid monofin
Not included	Mermaid tail fabric skin, goggles, swimwear

Why Choose This Monofin

Quick-release straps - the foot straps are designed to come off fast, which is the single most important feature on any monofin.
Adjustable - elastic straps take a range of foot sizes rather than one, so it lasts more than a single summer.
Soft silicone - flexible enough to kick comfortably and to avoid the rubbing that stiff fins cause across the top of the foot.
Builds a real skill - the dolphin kick it forces is a genuine swimming technique, not just a novelty movement.
Four colours - so siblings can tell theirs apart, which matters more at a pool party than it sounds.

How Is a Monofin Different From Normal Swim Fins?

Normal fins are a pair, one per foot, and they let the legs move independently - you can still flutter kick, tread water, and separate your legs to stand or recover. A monofin joins both feet into a single blade, so the legs move as one. That produces far more propulsion for the effort, which is why it feels fast and fun, and it is also exactly why it needs more care: a child in a monofin cannot separate their legs to tread water or to right themselves in the way they instinctively would. The technique is a dolphin kick from the hips rather than a kick from the knees.

Does a Child Need to Be a Confident Swimmer First?

Yes. This is not a product for a child who is still learning to swim, and it is not a flotation aid. A monofin binds both legs together. A confident swimmer treats that as a fun constraint; a weak swimmer treats it as a problem they cannot solve, and the instinct to separate the legs and stand up will not work.

Our recommendation, plainly: use it only with a child who can already swim comfortably and unaided in the depth of water they are in, only in a supervised pool, only with an adult within arm's reach, and not in the ocean, a river, or anywhere with current, surf or depth the child cannot stand up in. Teach them to release the straps before they go in - and have them practise it once on the pool edge - so getting out of it is automatic rather than something they have to work out while tired.

How Do You Learn the Dolphin Kick?

Start at the wall in shallow water with an adult holding on. The movement begins at the hips, not the feet: press the chest slightly down, let the hips rise, then let that wave travel down the legs so the fin finishes the stroke. Most children start by bending their knees and kicking like a bicycle, which goes nowhere and is tiring; the fix is to think about pushing the hips rather than the feet. Arms stay stretched in front with hands together. Short bursts of a few metres work better than long attempts, because the muscles used are ones children do not normally use in the water and they tire quickly.

Buyers are typically parents of primary-school-aged children who already swim, families with a backyard pool, and people buying a birthday or Christmas present for a child who is into mermaids. Swim clubs also use monofins for kick training.

For more, see our Summer range, Sports and Fitness, and Kids Supplies.

Frequently Asked Questions

Does it come with a mermaid tail?
No. This is the fin only - the fabric tail skin that goes over it is a separate item and is not included.

Why is there a goggles option on this listing?
A separate product has been attached to this listing as a variant, which it should not be - goggles are not a version of a monofin. We are separating them. If you want goggles, message us so we can make sure you receive the right item.

What shoe size does it fit?
The supplier gives an age range of 5 to 10 years but no foot size range, and the stated dimensions of 16 x 2 x 15cm look small for a monofin. We have queried both with the supplier. If foot size is a concern, message us before ordering.

Can an adult use it?
No. It is sized and rated for children up to about 10.

Is it safe in the ocean?
We would not use it there. Currents, surf and depth are exactly the conditions where having both legs bound together stops being fun. Supervised pools only.

Does it help a child learn to swim?
No - it is not a swimming aid and it provides no flotation. It is for children who can already swim.

How do you get it off quickly?
The straps are quick-release. Have your child practise taking it off at the pool edge before they use it in the water.

Fast Australian Shipping

We dispatch from within Australia, so orders reach Sydney, Melbourne, Brisbane, Perth, Adelaide, Hobart, Canberra and Darwin quickly ahead of the swimming season. Regional and remote addresses go through the standard Australia Post network.

Dimensions and age range are as supplied by the manufacturer and are being confirmed. THIS IS NOT A FLOTATION DEVICE AND IT IS NOT A SWIMMING AID. It restricts leg movement by design. Use only with children who can already swim unaided, only in a supervised pool, and only with an adult within arm's reach at all times. Never use in surf, current, or water out of the child's depth.

Mermaid Tail Swimming Fin - Kids Adjustable Monofin, Ages 5 to 10

Available Options