"Only fifty-five feet."
"What depth can you go?"
"The Navy Regulations forbid our descending more than two hundred feet. Subs are always hiking around about fifty or seventy-five feet under, just deep enough to be well under the keel of anything going by."
"Where are we now?"
"Pretty close to the mouth of the bay. I'm going to shove up the periscope in a few minutes."
The captain gave an order, the arrow on the dial retreated towards the left.
"Keep her there." He applied his eye to the periscope. A strange, watery green light poured out of the lens, and focussing in his eye, lit the ball with wild demoniac glare. A consultation ensued between the captain and his junior.
"Do you see her?"
"Yes, she is in a line with that little white barn on the island.... She's heading down the bay now.... So many points this way (this last direction to the helmsman) ... there she is ... she's making about twelve ... she's turning, coming back ... steady ... five, ... six ... Fire!"
There was a rush, a clatter, and a stir and the boat rose evenly to the surface.