Q 01/05

What does the acronym SONAR stand for?

A) Sound navigation and ranging

B) Sound observation and recording

C) Submarine oscillating navigation array

D) Sonic navigation and radar

Answer · why

A) Sound navigation and ranging

The study of underwater sound itself is called hydroacoustics.

Q 02/05

Which kind of sonar emits pulses of sound and listens for the echoes?

A) Bistatic

B) Active

C) Towed

D) Passive

Answer · why

B) Active

Passive sonar gives away nothing, which is why submarines rely on it most of the time.

Q 03/05

Who is recorded as first using a tube in the water to detect ships by ear, in 1490?

A) Christopher Columbus

B) Galileo Galilei

C) Leonardo da Vinci

D) Isaac Newton

Answer · why

C) Leonardo da Vinci

Underwater bells were later hung near lighthouses in the 19th century to warn ships of hazards.

Q 04/05

Which 1912 disaster prompted the first patent for an underwater echo-ranging device?

A) The Lusitania sinking

B) The Halifax Explosion

C) The Empress of Ireland sinking

D) The sinking of the Titanic

Answer · why

D) The sinking of the Titanic

Richardson was a meteorologist; a German, Alexander Behm, patented an echo sounder the following year.

Q 05/05

Which Canadian engineer detected an iceberg by echo ranging off Newfoundland in 1914?

A) Reginald Fessenden

B) Guglielmo Marconi

C) Robert Boyle

D) Alexander Graham Bell

Answer · why

A) Reginald Fessenden

His oscillator worked at about 500 Hz and could give range but not bearing.