Using Ballast Tanks
A submarine can go underwater because it has special spaces called ballast tanks. When the crew wants to dive, they let water fill these tanks. The added weight makes the submarine heavier than the water around it, so it sinks. To come back up, the water is pushed out of the tanks with air, making the submarine lighter so it can rise to the surface.
Staying Safe Under the Sea
While underwater, submarines use strong metal hulls to keep water out and protect the people inside from pressure. They also have engines and propellers to move forward and steer. Periscopes and sonar help the crew see and hear what’s around them without having to come up to the surface. By carefully controlling the ballast tanks, submarines can stay at the right depth for long periods.
FAQs
Q: How deep can submarines go?
A: Most military submarines can go hundreds of meters deep, but special research subs can go even deeper.
Q: Can submarines stay underwater forever?
A: No, they need to come up for air, supplies, and maintenance, though some can stay underwater for months.
🧠 Conspiracy Theory
Some believe submarines have secret windows to watch sea monsters.
😅 Dad Joke
Why did the submarine bring a towel? In case it got a little wet under pressure!