First off will be submersible devices—"You can call them swimming machines," he said—deployed to survey the damage.
He spoke of the gun emplacement as being in a swamp and I have a strong idea that it is submersible.
A steel ladder ran down into the interior of the submersible.
One of the great problems of the submersible has been to master the difficulties of its control while maintaining a desired depth.
The submersible was sighted on July 1, 1915, by a French aeroplane.
The third method by which to frustrate the attack of the submersible is to give better protection to the merchant marine itself.
Most of the payments on the submersible had already been made.
The submersible was of good size, being over two hundred feet in length.
Then it would be difficult to see how the submersible could be dealt with.
The submersible must be driven below the surface by a superiority of gunfire on the part of the merchant marine and its patrols.