Under the Sea Party Ideas: Games & Decor
An under the sea party without a single costume required — jellyfish games, crab-claw snacks, a bubble-wrap wall, and a printable invitation any kid can send.
Chanel Hoole7 min read
the bubble wrap gets more attention than the cake
An under the sea party is the ocean theme with no costume attached, and that is its whole advantage. Every kid at an aquarium tank belongs there without dressing up, and the same is true here: crabs, jellyfish, starfish and bubbles are things you make and hang and eat, not things a guest has to put on. It suits a group where half the invite list would rather not wear anything themed at all.
What follows is an under the sea party built on that idea — games about tides and creatures rather than characters, food in ocean colors, decorations made mostly from paper and bubble wrap, and a printable invitation. It works as well in a living room with the curtains drawn as it does on a pool deck.
The bubble-wrap wall, which costs nothing
Tape a full roll of bubble wrap to a wall or a stretch of fence at kid height, bubble side out. It catches light like water, it is genuinely satisfying to press and pop a section of, and it turns a blank wall into the single most-touched decoration at the party for the price of a roll you probably already have from the last thing that got shipped to the house.
Pair it with a blue cellophane or streamer overlay taped in loose waves above it, and the wall reads as water from across the room. It comes down in under a minute at cleanup, which is more than can be said for almost anything else on this list.
Running the afternoon
Open with the jellyfish wiggle while guests are still arriving — it needs no equipment and nobody has to have heard the rules to join in. Move to the crab-claw toss once the group is complete, since it needs everyone paying attention at once. Follow with the tide tug-of-war as the big physical game, then food, then something calm to hand kids back to their parents in one piece.
Every kid at an aquarium tank belongs there without dressing up. This party works the same way.
What actually goes wrong
Blue food coloring in punch and jello stains small mouths and occasionally a shirt, so keep it off light-colored furniture and have wipes closer than you think you'll need them. The bubble-wrap wall will get overpopped in the first ten minutes if you hang the whole roll at once — hang half and keep the rest as a reserve to swap in when the first section goes quiet.
The other failure is treating this as the same party as a mermaid theme and running out of ideas that aren't tails and shells. Keep it about creatures and habitat instead: crabs that pinch, jellyfish that wobble, an octopus with too many arms to count. If you'd rather someone else led the games, a party character performer who works in an ocean or bubble-show style will run the afternoon and take the wipes-and-wobbling off your hands.
Games for an under-the-sea party
Jellyfish wiggle
Everyone wiggles their arms overhead like jellyfish tentacles while the music plays and freezes mid-wobble when it stops. It's the instant opener, since nobody needs a rulebook to join in while the room is still filling up.
Starfish freeze
Guests move through the room and strike a starfish pose — arms and legs spread wide — the instant the music cuts out. Best pose wins the round rather than first to freeze, which keeps the youngest guests genuinely in the running against the oldest.
Pass the pearl
A small prize wrapped in a dozen layers of blue tissue paper, passed around a seated circle while the music plays. It's the reliable calm-down game once the group has been moving all afternoon, and it needs nothing more than tape and something small to wrap.
Tide tug-of-war
Split the group into two teams either side of a line drawn in chalk or marked with a rope, and pull. Naming the line the tide and each team an ocean current is the whole theming job, and it burns off more energy in two minutes than almost anything else on this list.
Crab claw toss
Toss bean bags into a bucket or a chalk circle drawn on the ground, standing in for a crab pinching its catch. It needs almost no space, it works indoors as well as out, and even a three-year-old can land one from a step closer.
Wave toss
Pairs toss a water balloon back and forth, stepping apart a pace after each successful catch, until the balloon breaks. It only needs a backyard and a hose, and it's the game that turns into the whole party if you let it run long.
Food ideas for an under-the-sea party
Ocean water punch
Lemon-lime soda tinted blue with a few drops of food coloring or a splash of blue sports drink, served over ice in a clear pitcher so the color does the work. It costs less than a specialty drink mix and holds its color for hours on a table.
Goldfish cracker reef
A big bowl of goldfish crackers poured over a bed of blue-tinted coconut or crushed graham crackers standing in for water, with a few gummy sharks or fish pushed in at the surface. No cooking involved and it refills from one more bag when it runs low.
Jellyfish snack cups
A dollop of vanilla pudding or yogurt in a clear cup with thin strips of licorice or fruit leather draped over the side as tentacles. Ten minutes to assemble a dozen, and they hold their shape on a table for an hour without melting.
Octopus hot dogs
Slice the bottom two-thirds of a hot dog into eight strips lengthwise before boiling — the strips curl outward into legs as they cook. Serve with a dot of ketchup for eyes. Kids who won't touch a themed vegetable tray will eat these without noticing they're the same hot dog they always have.
Blue wave jello cups
Blue gelatin poured into clear cups in two layers a few hours apart, with a gummy fish suspended between them so it appears to float mid-water. Make the day before — the layers need real time to set and there's no shortcut around that.
Decoration ideas for an under-the-sea party
The bubble-wrap wall
A full roll of bubble wrap taped to a wall or fence at kid height, bubble side out, with blue streamers taped above it in loose waves. It reads as water from across the room and it's the most-touched decoration at the party for the price of a roll you likely already own.
Hanging paper jellyfish
Paper lanterns or crumpled tissue balls with long strips of crepe paper streamer glued underneath as tentacles, hung from a ceiling or a tree branch at different heights. Three or four scattered around a room reads as a whole float of jellyfish for under ten dollars.
A cardboard octopus centerpiece
A round balloon or a painted paper mache ball for the head, with eight strips of purple or pink crepe paper or pool noodle glued underneath as legs, curled at the ends. It stands on its own on the food table and it's the thing every kid points at first.
Balloon ombre in ocean blues
Balloons in three or four shades from pale aqua to deep navy, clustered darkest at the bottom to palest at the top against a wall, reading as water depth without a single wave prop. Air-filled works as well as helium and costs nothing extra to fill.
A sand-and-shell centerpiece
A shallow tray or bowl filled with play sand or brown sugar, a handful of real or paper shells pressed in, and a few plastic sea creatures poking out. Fifteen minutes to build and it survives being poked by every kid who walks past the table.
Two more things worth sorting before the big day: where to buy the plates, balloons and piñata and what the whole party is likely to cost
Printable under-the-sea invitation
Free to download and print at home — write in the date, the time and the address, and it is done. It prints cleanly on ordinary paper at A5 or half-letter, two to a sheet, and it works just as well sent as a picture message if you would rather not chase a class list for addresses.
The under-the-sea invitation
One card, blank where the details go. Drop your email and it's yours — print as many as you need, nothing to pay.
Hire an ocean-themed entertainer
Everything above assumes you are running the afternoon. You do not have to. A character performer arrives in costume and in character, runs the themed games, handles the child who is frightened and the child who wants to be the star, and gives you an hour to put the candles in the cake — which is usually the difference between hosting the party and watching it.
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Frequently asked questions
- What age is an under the sea party best for?
- Two to eight, and it holds a wide age range better than most themes because nobody has to costume up to take part. Under-fives are happy with the bubble wall and the jellyfish wiggle; six- to eight-year-olds want the tug-of-war and the wave toss to actually be a contest.
- How is under the sea different from a mermaid party?
- Under the sea is creatures and habitat — crabs, jellyfish, an octopus, a bubble-wrap wall — and needs no costume at all. A mermaid party is built around wearing a fabric tail. Pick under the sea if you want a theme every guest can join without dressing up.
- How do you throw an under the sea party on a budget?
- A roll of bubble wrap, blue crepe paper streamers and a couple of balloon bags cover the whole room for under fifteen dollars, and none of it needs to be bought as a themed set. The bubble-wrap wall alone does more visual work than most store-bought backdrops.
- What food do you serve at an under the sea party?
- Anything blue with a sea creature standing in the name works. Ocean water punch, a goldfish cracker reef, jellyfish pudding cups and octopus hot dogs cover the whole table with nothing more exotic than food coloring and a kitchen scissor.
- How long should an under the sea party last?
- Two hours suits most ages. That's roughly twenty minutes of arrivals and the jellyfish wiggle, twenty on the crab-claw toss, half an hour of the bigger games, half an hour for food and cake, and a calm game left for pickup.
Written by
Chanel HooleParty planning editor at Yombu
Chanel writes Yombu's guides to kids party entertainment — the planning playbooks that help busy parents pull off a celebration without the stress. She has spent years tracking what actually makes a children's party land, from the entrance an entertainer makes to the games that keep a room of six-year-olds spellbound.
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