National Submarine Day (April 11)
National Submarine Day is celebrated on April 11 and marks the moment the U.S. Navy officially accepted its first modern submarine, the USS Holland, in 1900.
If your kids are even slightly curious about the ocean, this is one of those surprisingly fun weird holidays in April to lean into.
It’s an easy excuse to talk about how submarines work, why they matter, and how humans manage to explore places we can’t even see.
When is the Holiday?
It’s celebrated every year on April 11th. This date marks the anniversary of the U.S. Navy officially accepting the USS Holland (SS-1) into service in 1900.
Who Invented It?
There isn’t a clear “founder” of the day, which is pretty common with these types of holidays.
It’s more something that’s been picked up over time by naval groups and history enthusiasts. It does, however, center around John Philip Holland, who designed the USS Holland and is usually credited with creating the first practical modern submarine.
The History of the Holiday
This one really comes down to a single moment in 1900 when the U.S. Navy accepted the USS Holland.
It doesn’t sound huge, but it ended up changing both naval strategy and how we explore underwater. Before that, submarines were more experimental than useful. After that, they became something countries actually relied on.
Now they’re used for everything from defense to researching parts of the ocean we still don’t fully understand, which is probably the part kids find the most interesting.
Top 5 Facts About the Holiday
- The USS Holland used gasoline on the surface and switched to electric power underwater, pretty advanced for 1900.
- One of the earliest submarines, called the Turtle, was used during the American Revolutionary War (and only fit one person).
- The USS Nautilus became the first nuclear-powered submarine in 1954, meaning it could stay underwater much longer.
- Modern submarines aren’t just military, they’re used to study deep-sea ecosystems and marine life.
- The song Yellow Submarine by The Beatles helped turn submarines into a pop culture icon.
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Coloring Page
If you want something really simple to go with this, the submarine coloring page below works well.
It’s one of those easy wins, kids can get started straight away while you chat about how submarines work or what they’re used for. I’ve found even reluctant learners will sit down for this kind of activity if it involves coloring first.
Activities to Celebrate
If you happen to live near a submarine museum, it’s worth going at least once. Places like the USS Nautilus Museum or the USS Bowfin let you walk through a real submarine, and it’s usually much smaller inside than kids expect, which always surprises them.
If you’re staying home, a short documentary works well. You don’t need a full lesson, just seeing how a submarine dives or how people live inside one is usually enough to spark questions.
Books are an easy option too, especially for younger kids. The Magic School Bus on the Ocean Floor is a good one because it explains things without feeling too technical.
For something more hands-on, you could build a simple model submarine. It doesn’t need to be anything complicated, just enough to get them thinking about how it’s designed and how it moves.
And if the conversation naturally goes that way, this is a nice opportunity to talk about ocean life and conservation. Submarines are a big part of how we study the ocean, so it links quite naturally.
Links to Resources
If you want to extend the learning a bit further, these are a few easy add-ons that work well alongside the activities above.
- Yellow Submarine Craft with Free Template. A creative and fun activity for kids to make their own submarine craft inspired by the iconic Yellow Submarine.
- Revell 1:72 German U-Boat Model Kit – A detailed model kit for submarine enthusiasts, offering an intricate build and historical accuracy.
- LEGO Creator 3-in-1 Deep Sea Creatures – A fun and educational LEGO set that includes a buildable submarine, perfect for young learners.
- Super Submarines. A fantastic children’s book introducing young readers to submarines with fun rhymes and engaging illustrations.
Related Holidays
This isn’t the only holiday that celebrates innovation and exploration.
- National Lighthouse Day on August 7 highlights the importance of lighthouses in maritime history, guiding sailors safely to shore.
- Hot Air Balloon Day on June 5 honors the ingenuity behind early aviation and the spirit of adventure that took humans to the skies.
- Amelia Earhart Day on July 24 commemorates the pioneering aviator who pushed the limits of flight, much like submariners have expanded our understanding of the ocean depths.
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