What does a submarine do to dive?

Floods its ballast tanks with water

Blows water out with compressed air

What are diving planes?

Movable fins that angle the sub up or down

The depth at which the hull would fail

Submarine Buoyancy Quiz: Ballast Tanks and Diving Planes

This submarine buoyancy quiz dives into the science that lets a steel boat sink, hover and rise on command. Play 10 interactive questions on Archimedes' principle, ballast tanks, compressed air, trim tanks, diving planes, neutral buoyancy, pressure hulls, crush depth, the Turtle, the Hunley and USS Nautilus.

Start Submarine Buoyancy Quiz

🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 150 Seconds

Question 1 / 10 Time: 150s

Principle
Which principle explains why submarines float or sink?
Dive
What does a submarine do to dive?
Surface
How does it surface?
Neutral
What is neutral buoyancy?
Trim
What do trim tanks do?
Planes
What are diving planes?
Hull
What protects the crew from water pressure?
Crush
What is crush depth?
Hunley
What was the Hunley the first to do in 1864?
Nautilus
What was USS Nautilus the first to be?

Explanations: answer key for all 10 questions

Q1: Which principle explains why submarines float or sink?
Answer: Archimedes' principle
It is about displaced water.
Q2: What does a submarine do to dive?
Answer: Floods its ballast tanks with water
Extra weight makes it sink.
Q3: How does it surface?
Answer: Blows water out with compressed air
The tanks fill with air again.
Q4: What is neutral buoyancy?
Answer: Neither sinking nor rising
The sub can hover.
Q5: What do trim tanks do?
Answer: Make small balance adjustments
They keep the sub level.
Q6: What are diving planes?
Answer: Movable fins that angle the sub up or down
They work with forward speed.
Q7: What protects the crew from water pressure?
Answer: A strong pressure hull
It resists crushing force.
Q8: What is crush depth?
Answer: The depth at which the hull would fail
Subs stay well above it.
Q9: What was the Hunley the first to do in 1864?
Answer: Sink a warship
It was a Confederate submarine.
Q10: What was USS Nautilus the first to be?
Answer: A nuclear-powered submarine
It passed under the North Pole in 1958.

Submarine Buoyancy Quiz – Ballast Tanks and Diving Planes

A submarine floats or sinks according to Archimedes' principle. When it weighs less than the water it displaces it floats, and when it weighs more it sinks.

To dive, the crew floods ballast tanks with seawater; to surface, compressed air blows the water out. Trim tanks fine-tune balance, and diving planes angle the boat up or down as it moves.

A strong pressure hull protects the crew, and each design has a crush depth it must never reach. The Hunley sank a warship in 1864, and USS Nautilus, the first nuclear submarine, passed under the North Pole in 1958.

What This Quiz Teaches

Science fans will enjoy these questions.

How submarines float
How they dive and surface
How they stay level
What protects the crew
Which subs made history

Did You Know?

Fish use a swim bladder in a similar way.
The Turtle tried to attack a British ship in 1776.
Snorkels let diesel subs run engines just below the surface.
Nuclear subs can stay underwater for months.
Sonar helps submarines navigate in darkness.