"Of course it is; who did you think it was?" asked Bill.
"What are you doing on deck in your night shirt?" asked the boy, letting the helper rise.
"Me? On deck? Ain't I in my bunk?"
"I should say not," replied Jack. "What are you doing on deck?"
"Well! well!" remarked Bill, rubbing his eyes. "I've gone and done it again."
"Done what?"
"Walked in my sleep. I'm a great sleep walker. Greatest you ever knew. Once I climbed to the top of our barn when I was asleep."
"So you're the ghost of the submarine," exclaimed Jack. "That explains it."
"I guess you're right," admitted Bill, as the others came on deck to see what all the row was about. "I never thought of it when I heard about the ghost, but I can account for it now. I'd get out of my bunk, wander out on deck, and then crawl back again. Of course, being barefoot, or in fur slippers, I made no sounds. I don't wonder you thought I was a spirit. Queer I didn't wake up after some of the things I went through."
"And you always managed to get back to your bunk in time so that we never caught you at it," said Jack. "However, it's all over now."