To give your mermaid tail structure and swim like a real mermaid, you will need to insert a monofin.
Children (with adult supervision) can swim faster and more efficiently using what is known as the 'dolphin kick', using the monofin.
Easy to get on and off, these are lightweight and particularly comfortable to wear (we find the plastic or rubber ones can pinch the skin). The central plastic fin is covered in soft, flexible neoprene material that cocoons the ankles like a pair of socks.
We stock two sizes of monofins and up to six sizes of mermaid tails. The tail size 130 (suitable for approximately 7-8 year olds) sits somewhat in the middle of the two monofin sizes.
If your child has size 12 feet or smaller go for the small, if your child has size 1 or above feet, we would recommend getting the larger size as it is important that in the water they can quick release their feet if need be (please read safety advice).
Also, once you have the larger one, you won't need to replace it, just update the mermaid tail as she grows!
Getting out of a mermaid tail is accomplished by wiggling your feet until at least one of them is out of the monofin, and pushing the tail down from the waist with your hands. Once one foot is free, you can use that foot and your hands to help release the other. Then simply swim out of your tail.