Great screws such as are used in raising buildings were also employed under wharves sometimes.

There were rocks under some wharves, and water was under others.

Whichever it was, Willis' father often had to go under the wharves and climb around among the caps and stringers and piles, repairing.
Seven or eight other men were employed like Mr.Sutherland.It was mid-forenoon, but Willis saw that three or four of the men were not working.

They were idling around the engine of the pile-driver, and were eating something that Willis found to be cooked crabs.
"Where's father ?" asked Willis.

"Under the wharf, working," answered one man.