The Z99, he went on, is a submersible, not a diving, submarine.
"The Dream Doctor"
Arthur B. Reeve
For example, a distinguished naval writer says that at that time The view of the majority of admirals and captains probably was that submersible craft were 'just marvellous toys, good for circus performances in carefully selected places in fine weather.
"The Victory At Sea"
William Sowden Sims Burton J. Hendrick
But the German submersible swerved just a trifle and the torpedo missed by a narrow margin.
"The Boy Allies Under the Sea"
Robert L. Drake