British frogman Lionel Crabb prepares for dive mission in 1950

Commander Lionel Crabb, a veteran of undersea missions during World War Two, prepared for a mysterious dive with enough oxygen to last several hours. His mission was not publicly known, and his appearance caused diplomatic tensions. Despite England's statement of no permission for the dive, Crabb was never seen alive again, leaving his fate a mystery.

What was Commander Crabb's role during World War Two?

• A spy for the British government

• A commander of a naval fleet

• A veteran of undersea missions

• A pilot in the air force

What was the public's reaction when Commander Crabb was spotted?

• They celebrated his mission

• They were supportive

• They were indifferent

• There was a furor

Which countries were involved in the controversy surrounding Commander Crabb's dive?

• Japan and China

• Germany and Italy

• United States and France

• Great Britain and Soviet Union

What was England's official response to the dive?

• They denied giving permission

• They remained silent

• They gave permission

• They issued a warning

What is known about Commander Crabb's fate after the dive?

• He was never seen alive again

• He was captured

• He was found alive

• He returned safely