How do I make an easy DIY Under the Sea costume?

Wear a solid blue or green outfit and hot-glue plastic sea creatures, faux seaweed, and seashells onto a headband or the shoulders of your shirt.

What are some funny Under the Sea pun costumes?

You can go as a 'Deviled Egg' (wearing devil horns and a yellow egg belly) but underwater-themed, or a 'Sea-Sponge' by attaching kitchen sponges to a blue shirt.

How do I make a jellyfish umbrella?

Take a clear dome umbrella and attach long strips of iridescent ribbon, lace, yarn, and bubble wrap to the rim using clear tape or hot glue.

AI-generated example

Under the Sea

Bring the magic of the ocean to life with aquatic-themed costumes.

An Under the Sea themed costume is a vibrant, creative choice perfect for parties, group themes, or solo dress-up. Inspired by marine life, coral reefs, and mythical ocean creatures, this look can range from a shimmering mermaid to a deep-sea diver or a colorful jellyfish. It is a highly customizable theme that allows for plenty of DIY creativity and bright, oceanic colors.

Difficulty: Easy
Time: ~45 min
Budget: $20–80

See yourself in one of these →What you need

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See yourself as Under the Sea

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Under the Sea costume — Example look · AI-generated

You as Under the Sea

Result

40 Under the Sea costume ideas

Ranked by how many people are searching for them this season. Open any one for the full guide and to try it on.

What you need for a Under the Sea costume

Ocean-colored base layer
A solid teal, blue, or green bodysuit, dress, or t-shirt to represent the water.
DIY: Use a plain blue or green t-shirt from your closet.
Amazon
Iridescent or metallic scales
A sequined skirt, metallic leggings, or scale-patterned fabric to mimic fish or mermaid scales.
DIY: Cut scale shapes out of shiny craft paper or felt and fabric-glue them to an old pair of leggings.
Amazon
Seashell accessories
A crown, hair clips, or jewelry decorated with faux starfish, seashells, and pearls.
DIY: Hot-glue real seashells and plastic pearls onto a plain plastic headband.
Amazon
Jellyfish umbrella or prop
A clear bubble umbrella with hanging ribbons, tulle, and LED fairy lights to mimic tentacles.
DIY: Tape blue, white, and purple curling ribbons and bubble wrap strips to the inside rim of a clear umbrella.
Amazon

How to put it together

1
Put on your ocean-colored base layer, such as teal leggings and a matching top.
2
Layer on your scale-patterned garments, like a sequined skirt or metallic pants.
3
Secure your seashell headband or hair clips into your hair.
4
If creating a jellyfish look, open your decorated clear umbrella and turn on the LED fairy lights.
5
Apply shimmering face glitter or metallic makeup to complete the aquatic aesthetic.

Makeup & hair

Style hair in loose, beachy waves or a sleek wet-look style. Use shimmering blue, green, or silver eyeshadow, and apply biodegradable cosmetic face glitter along the cheekbones for a wet, sparkling underwater effect.

Under the Sea for couples, groups, kids & more

couples: One person dresses as a mermaid with a sequined tail, while the other goes as a retro deep-sea diver with a bronze helmet and dark jumpsuit.
group: Coordinate an entire ocean ecosystem with friends dressing as a shark, a jellyfish, a lobster, a sea turtle, and a scuba diver.
kids: A simple shark onesie, a colorful plush crab suit, or a sparkly mermaid tail skirt.
Plus size: A flowy, ocean-blue maxi dress paired with a seashell crown and a glittering sheer cape mimicking water currents.
pet: A cute shark fin harness or a plush lobster costume for dogs.

Tips

If using a jellyfish umbrella prop, make sure the hanging ribbons are cut short enough so you do not trip over them.
Keep warm in cool weather by layering skin-toned fleece leggings under sequined skirts or fishnet stockings.
Use waterproof makeup and setting spray to ensure your shimmering ocean face paint lasts all night.

Under the Sea costume FAQ

How do I make an easy DIY Under the Sea costume?: Wear a solid blue or green outfit and hot-glue plastic sea creatures, faux seaweed, and seashells onto a headband or the shoulders of your shirt.
What are some funny Under the Sea pun costumes?: You can go as a 'Deviled Egg' (wearing devil horns and a yellow egg belly) but underwater-themed, or a 'Sea-Sponge' by attaching kitchen sponges to a blue shirt.
How do I make a jellyfish umbrella?: Take a clear dome umbrella and attach long strips of iridescent ribbon, lace, yarn, and bubble wrap to the rim using clear tape or hot glue.

Did you know? The iconic song 'Under the Sea' from Disney's The Little Mermaid was heavily influenced by Caribbean Calypso and Jamaican Reggae music, winning the Academy Award for Best Original Song in 1989.