DIY Underwater Birthday Party Themes

My daughter, Chesney, wants to be a marine biologist when she grows up. (I did too when I was her age.)

So, for her 9th birthday, I decided to try a DIY underwater theme. I’ve included affiliate links where applicable to the products I used for these party themes.

Room decorated for an under the sea party.

Not bad for totally winging it. 🙂

DIY Party Themes – Under the Ocean


As party themes go, this one is certainly a winner. For this DIY Underwater Party, it’s all about the decorations.

If you don’t really feel like you’re underwater, then what’s the point?! So, I wandered into Michael’s and let my imagination guide me… but let my wallet make the final decisions.

I achieved this awesome look for an affordable amount! I simply purchased one blue and one light purple iridescent roll of transparent wrap, clear balloons, a few glow bracelets and some ribbon.

For the rest, I just dressed up some ordinary household items.

DIY Jellyfish for Underwater party themes.

The jelly fish are just up-side-down colanders with ribbon tied to their centers. If you don’t have any of these, any upturned bowls would do the trick.

DIY Underwater party themes.

I just love the way the colors turned out with the sun streaming through the window. All we did (this is more of a two person job, or you may drive yourself crazy,) was slightly overlap the transparent wraps and those colors were the result! We used packing tape to secure each side to the window/door frame.

I had a few small plastic treasure chests left over from Jen’s pirate themed bridal shower so I set those between the window and plastic.

I blew up the balloons, aka bubbles, and made sure to under-fill some for a variety of sizes.

I found a squishy fish-like creature in the kids’ toy chest and suspended that using fishing line and a removable 3M® hook.

I set my beloved pineapple plants in front of everything for the finishing touch.

It’s all about the details. Even the birthday invitation was under the sea themed.

Kids at an underwater themed party.

While the girls played fun games like Go Fish! they really did feel like they were on the bottom of the ocean.

This was a sleepover party, so once the sun went down, we used our Tranquil Turtle to keep the ambiance going in the dark. I put glow sticks into the soap dispensers so that the girls could find the bathrooms without having to turn on all the lights.

Glow sticks in soap dispensers.

Snack and Drink Ideas

A Twist on Party Favors

Instead of doing goodies bags filled with candy and cheap garbage, we did a DIY Mini Aquarium activity with Baby Marimos! The girls loved this activity and got to take their pet home! Please check out how to make your own Mini Aquarium here! Just look how cute the girls are with their new little Marimo friends! 🙂

Kids at an under the sea themed party.

Chesney had an awesome 9th birthday party and received some super fun gifts!

Check out her spiffy new underwater gear! Birthday party themes like this are such a blast!

Chesney in a snorkling mask.

Mermaid recipe ideas for an underwater party

Who do you know that would love an underwater birthday party theme?

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  1. The colors and the idea to have an underwater themed birthday for your daughter is amazing. I like the colors they are so pretty. And the snack ideas are great because they really go with the theme. I bet your daughter really liked her birthday party!

  2. You, ma’am, are one creative mamma! For winging it you did a seriously incredible job!
    It looks like the girls had a lot of fun 🙂

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