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Monofin Features

Sun Tail Mermaid Monofin Features   

  • A specially engineered plastic fin is far more durable than brittle plastics that crack even under normal use.
  • Function hidden in beauty! The fin's realistic fish-tail like ridges add strength to keep the monofin from breaking.
  • Flexible, but not too flexible! Our monofin aids in propulsion better than the competition while keeping feet secure and still remaining comfortable to wear.
  • We've eliminated stiff rubber foot pockets and uncomfortable straps that cause blisters. Our soft foot pocket is stretchy and self-adjusts to fit a wide range of foot sizes!
  • Unique design separates your feet comfortably - soft fabric cushions your feet (they don't rest on plastic). Your feet are comfortably encased in individual foot pockets; ankles and heels won't bang together, and your feet don't slide around inside. This makes performing fancy mermaid turns and flips much easier!
  • Our twice-patented design provides form and function.
  • It comes in fun colors so you can wear your monofin all by itself, and it's still easy to see in the water. Swimmers who aren't into a mermaid tail skin love wearing monofins alone.


The Keiki kid-sized monofin is 17" and 18.5" wide at its widest part -- it's small enough for younger mermaids while still looking really pretty and realistic on pre-teens. We recommend this size for kids age 6 - 12. It fits all the way up to a US women's size 7 foot.

The Nunui teen/adult sized monofin is 21" deep and 24" wide at its widest part and fits all the way up to a US men's size 13+ foot.


Handy tips

The neoprene foot pocket stretches a surprising amount once it's wet. If you are struggling to get your feet through the openings the first time, try getting it wet first.

As you swim and the foot pockets stretch, you might want to take the monofin off, and tighten the velcro. To keep your monofin from stretching out too much, after you swim, release the velcro and let it dry unfastened.  Note:  if you share your monofin with someone who has bigger feet than you, your foot pocket may stretch out so much that your own feet may no longer fit. 

Recommendations & Warnings

  • First, practice your mermaid kick (butterfly kick, sometimes called a dolphin kick (see video on youtube) without the monofin. Try holding onto the side of the pool at first.
  • Once you and your guardian feel comfortable, add the monofin. Hold onto the side of the pool and practice the mermaid kick while wearing the monofin.
  • As soon as you and your guardian feel comfortable, add the mermaid tail. Practice again and make sure you feel comfortable in the whole mermaid set before swimming away from the side of the pool.
  • Mermaid tails and monofins tend to make us feel magical and invincible! But be smart mermaids, don't swim in water that it is too deep for your abilities.
  • ALWAYS use with adult supervision.
  • Monofins are not swimming aids, and only strong swimmers should use them. In our experience monofins can help less experienced swimmers gain confidence and improve their swimming, but adult supervision is a must.

Caring for your mermaid monofin

Unlike other monofins, our swim fins do not require any babying. You can bounce on the tips, push off pool walls, even hop around in them without any fear of the fin breaking -- though you can break so please be careful.

Rinsing your monofin in plain water after you're done swimming is always a good idea. You can unfasten the velcro in the back and prop the foot pocket open to speed drying. The entire foot pocket can be washed with mild detergent and air dried if needed. Please don't put your foot pockets in the dryer, they may melt or warp.