Underwater world costume – 20 cool ideas for children and adults

Immerse yourself in the fantastic world under the sea, where the mermaids sing and the fish dance. Whether for carnival or for a theme party, a Underwater world costume would definitely cause a stir. In today’s article you will find great ideas that are easy to implement and are suitable for both children and adults.

Make underwater world costume yourself – 3 ideas for jellyfish costume

Underwater costume -jellyfish-do-it-yourself-ideas

With relatively little expenditure of time and money, you can make your own jellyfish costume. These ideas are super easy to implement and can also be adapted for children. The main component of a jellyfish body is its umbrella, from which hundreds of tentacles hang. Jellyfish move slowly through the water like ghosts and look very elegant.

Make jellyfish costume yourself – materials

Underwater costume jellyfish-making-materials

For all three variants you need the following materials and tools: various sheer / metallic fabrics, spray paint in silver, a cheap hoop skirt, an umbrella hat, a bell umbrella, scissors, and a hot glue gun. Optionally, battery-operated LED fairy lights, if you want to create a cool effect.

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Repurposing an umbrella hat

Underwater costume jellyfish-do-it-yourself-lady-umbrella-hat

A headshade provides shade and protection against rain and sun. It is attached to the head with a rubber band and can be purchased online at a reasonable price.

Color the colorful umbrella cap silver


The colorful headgear looks very funny, but for the mystical jellyfish costume it has to be painted silver. The spray paint is best used outdoors.

Strips of different fabrics

Underwater costume sea creatures jellyfish strips of fabric

Cut out many 2 cm wide strips from the various silver-colored and shiny fabrics. The more different the textures, the better.

Glue on strips of fabric

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Use a hot glue gun to attach the strips of fabric to the head visor. It would be better if more strips were glued at the back so you can see where you are going in the front. Cover the elastic band of the canopy with a satin ribbon.

Matching make-up in purple and silver

Underwater costume adult woman jellyfish umbrella hat

Put the umbrella upside down and ask a friend to trim the tentacles to the length you want. Combine the hat with a shiny dress. You can tie a few more decorative ribbons at the waist.

Make a hoop skirt yourself


Get yourself a cheap hoop skirt! This petticoat is basically worn under the dress and gives it more fullness. The hoop skirt is usually made of white fabric and can be purchased separately.

shorten the hoop skirt and remove rings


Measure the length from the waist to the desired skirt length and cut off the excess fabric. The shorter the hoop skirt, the more comfortably you can sit. Two rings are okay. Real DIY fans can also sew the hoop skirt themselves.

Spray the crinoline with paint


Polyester hoop skirts are cheap to buy and are perfect for this DIY costume. Spray the skirt inside and out with the silver-colored spray paint and let it dry.

Glue on strips of fabric

underwater-costume-jellyfish-skirt-do-it-yourself-hot glue gun

Glue the colorful stripes to the waistband of the skirt. Take three overlapping strips and glue them together so that they fall nicer at the bottom.

large white jellyfish from bell umbrella


The last jellyfish costume is all white and looks light and airy. For this purpose, a bell umbrella, which is deeper than a normal umbrella, was decorated with various white fabrics.

Fasten pieces of fabric and garlands with safety pins


Wrap the bell umbrella in the sheer fabric and pull the ends together at the bottom. Secure the fabric with safety pins and drape several ribbons, tinsel garlands or organza as tentacles.

Arielle the mermaid costume interpreted in a modern way


Disney’s fairy tale characters are a popular choice when it comes to carnival disguise. Ariel the mermaid has a green fin and a purple shell bra. However, these characteristic features can also be interpreted in a modern way.

Underwater world costume – reinterpreting Ariel’s top

underwater-costume-mermaid-mermaid-white-t-shirt-shell print

Use purple textile paint and a cardboard stencil to paint similar seashells on a white t-shirt. Pay attention to the correct size and position – not too big or too small and not above or below the breast. Then simply print out the template, cut it out with a craft knife, place it on a T-shirt and paint. The best thing to do is to put a piece of cardboard inside the shirt.

Make a tulle skirt for a mermaid costume yourself


You can create a beautiful skirt without sewing from tulle fabric in shades of blue and green. So that the tulle skirt looks like the split tail of the mermaid, it should be tied down in the middle. Green sequin leggings are also suitable as a fin.

Make a shell crown 

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The right accessories make a mermaid costume complete! Since Ariel is a Disney princess, she can of course also wear a crown. You can make these yourself quickly.

Decorate plastic crown


A princess diadem forms the basis, which is wrapped with silver pipe cleaners. The decoration is left to your imagination. In addition to shells, corals and starfish, you can also use rhinestones, pearls, crystals or chains.

Paint the shells and glue them to the crown


You can paint the shells with various acrylic paints with a pearlescent effect. Use shades that are reminiscent of the sea, such as turquoise, beige and navy blue. Glue the seashells to the crown with the help of the hot glue gun.

A net as a hair ornament for the underwater world costume

underwater costume mermaid accessories fishing net

A braided side braid goes perfectly with the mermaid costume! But if you don’t have long hair, you can rely on attractive hair accessories. This net, for example, was draped over the hair and fixed to the head with a decorative hair band.

Mermaid makeup

underwater-costume-mermaid-mermaid-make-up-net effect

Give your face a nice subtle shimmer by applying a highlighter or a powder with luminous pigments. On the forehead and cheeks you can dab blue, purple and green eyeshadows with the help of a sponge and even create an interesting mesh effect.

Underwater costume mermaid makeup pearl shell crown

Dory fish costume for toddlers


The girlfriend of the clownfish Nemo returned in 2016 with the new film “Finding Dorie”. The pallet doctor fish lady has a dark blue body, a yellow tail fin and large pink eyes. How can you use this information to make a fish costume?

Make fish costume yourself


Use felt to make Dory’s eyes. These can then be glued onto a dark blue baby romper suit. Don’t Forget Dory’s Fins! Each fin is made from a black and a yellow felt semicircle. Make small incisions on one edge and glue the pieces of felt to each shoulder. The costume is completed with a yellow tulle skirt and a headband. An interesting ombre effect can also be made on the yellow tutu with blue spray paint.

Make funny fish costume for baby yourself

underwater costume baby fish purple felt headband

Dress up your darling like a fish for carnival! The basis for the costume is a simple purple-colored baby sleeping bag. Overlapping semicircles made of felt in purple, green and light blue are glued to it, which are supposed to imitate the fish scales.

Spice up purple rompers or sleeping bags

underwater-costume-baby-fish-rompers-pieces of felt-fish scales

You can use a shimmering thin fabric for the fish fin. Cut a small styrofoam ball in half with a craft knife and glue the halves to an elastic baby headband. A small circle of black felt should be attached to each “eyeball”.