I just love birthdays. They have always been special to me, and now that I have kids, I get to do all the things I wish I would have done when I was a kid for them! And so, I do. And in case you’re like me, and you’ve got a kid who is wanting an Underwater Birthday Party or an Under the Sea Birthday Party, I’ve got lots of ideas for you.

Let me me break it down for you:

Underwater Birthday Party Invitation

Don’t ask me why, but somehow I got it in my head that I wanted the invitation to be watercolor based.

Now, why I felt I needed to hand paint them and hand letter them, I don’t know…sometimes I just get an idea in my head and I’ve got to do it. But nevertheless, I was really happy with how they turned out. If you want to create the same effect without as much work, you can download this free watercolor background and try out one of these fonts.

Underwater Birthday Party Decor

I saw these really neat plastic bag jellyfish on Pinterest, and I knew that I wanted to try to create them (though as I write this post, I realize I never clicked on the link and just made up my own instructions, but there are some in the link, too, so follow what you’d like!). The only problem was that I couldn’t find clear trash bags anywhere! I happened to have a few from some purchases at the fabric store, so I was able to eek out three jellyfish.

All you need is some tape, a bit of string, and some scissors. The basic premise is that you make a poufy ball at the end of the bag and then cinch it closed with string. I threaded the string through the top so that I could control how tall the head of the jellyfish was and secured it with tape once I got it where I liked it. Then you take scissors and make long and short strips of the remaining part of the bag.

I also made a school of giant tetra fish. I had some foil bubble wrap left at my house by my parents (they use Blue Apron and get these foil bubble wrap bags every week), so I repurposed it into fish. I cut them out and then added details with a sharpie. Some more string and tape will get these fish hung in no time.

And then streamers. Gotta have streamers and balloons. I owe the coolness of these streamers to my hubby. He was very diligent in getting them twisted and zig zagged just the right way. Way to go, husband!

The Underwater Birthday Party Attire

If you’ve followed our blog for a while and have seen my kids’ birthday parties, you know that I like to make my kids’ birthday shirts (see here, here, and here). It’s so easy with freezer paper, and I can make sure it matches my theme perfectly. And they end up being some of my kids’ favorite shirts to wear.

So for this one, I got a hooded shirt on sale and added a small shark on the front pocket that I mostly just eyeballed. Then on the sleeves, the part I was most proud of, I made teeth so that Elliot could chomp at people.

He was not really into the sleeves this party day, but I thought it was cool. Maybe for a slightly older child, it would work better.

Underwater Birthday Party Food

Sushi. Yep, I served sushi to a bunch of three year olds. I’m a genius. But actually it all basically got eaten. In fact, the raw fish ones were the only ones that got completely eaten. So there!

I actually had a friend coach me on how to make sushi, so I made a few varieties. I had a spicy tuna roll and a vegetable roll that used seaweed and traditional sushi food items. Then I made fruishi (fruit sushi) from coconut rice and chopped up fruit (strawberries, kiwi, raspberries). The fruishi was a little sticky, so I ended up rolling the whole roll in some unsweetened coconut flakes before chopping.

And then for the unadventurous, I had pb and j sushi, which is basically a rolled up version of the sandwich. I did learn that you don’t want to over fill it with peanut butter or especially jelly. And it helps to freeze the rolls before slicing to keep the roundness.

I also served salmon cakes as another way to get under the sea food for people who were unsure about raw fish. 🙂

And then the snacks. You can see in the pictures that I got to the labeling part of the buffet, so I tried to come up with clever names for all the food. Tortilla triangle chips – shark teeth; tortilla roll chips – sea anemone fronds; tortilla round chips – fish scales; cut up fruit – rainbow fish scales; cucumber – sea cucumber slices; celery – seaweed; etc.

Underwater Birthday Party Cake

Ah the cake! I actually decided to finish it the night before, and I am so glad I did. It allowed me to actually finish the cake and not be distracted by all the other last minute details before or while guests are arriving.

Elliot asked for a shark cake, so that’s what he got! I was inspired by this and this cake, but ultimately, I made the design my own. I don’t like doing rice krispie toppers because 1) I like more cake and 2) I haven’t mastered how to cover it smoothly with fondant, so I made the shark out of cake. I had to use a straw for support, but it mostly stayed up with frosting and gravity.

Underwater Birthday Party Games and Activities

For a craft, we made initials out of sand dough and decorated it with little shells that I found here.

We rolled them pretty thin on parchment paper, so after the kids had decorated them, I baked them for maybe 45 minutes on 200 degrees F, while other things were happening in the party. Even with two rotations, I was able to get everyone’s baked before they went home. We did make the craft the first activity of the party.

After lunch was eaten, we read one of our favorite books about an underwater sea creature, I’m the Biggest Thing in the Ocean. If you haven’t read it, please do. It’s short, but funny and quirky–the perfect recipe for a good book.

Then we played a version of hot potato, but instead of a potato, I decorated a spiky rubber ball, and I called it Pass the Puffer Fish. The idea was that you didn’t want to get poked by the puffer fish and be the one holding the ball when the music stopped. If they did, they were out, but they then got to go fishing in the tank for a prize for their goodie bags. I unfortunately don’t have a picture of the puffer fish game (I really need to learn to delegate a photographer other than me for party days!), but here’s one of the tank.

I just used a large clear plastic bin that I filled with about 16 bags of unhydrated water beads. Then I filled it with water, about halfway up my container. Overnight the bead hydrated and became squishy, slippery things perfect for running your fingers through. So I had the boys play a bit and hide the shark and fish figurines that I had ordered.

Underwater Birthday Party Favors

Aside from the figurines that they fished for, we gave out little bags that Elliot decorated with stencils and paint. I was really quite proud of his diligence (he did all the bags himself!) and his ability. I think the bags turned out quite nice.

Inside the bags were some chocolate shells I made from a mold (though I forgot to take a picture of it before they were all snarfed up) and some lifesavers. Easy but a hit.

Want more Ideas?

Check out our Birthdays Pinterest board to see other parties we’ve done and other parties we’d like to do!

And if you’re looking for more underwater birthday party ideas, check out my personal Pinterest board on just that!