It was a cold-blooded exhibition of marksmanship.

At first their bullets zipped harmlessly along the surface of the water on either side the boat; but, as the men continued to pull lustily, they struck closer and closer.
"Now, watch me take Kelly's right oar," Smoke said, drawing a more careful aim.
I was looking through the glasses, and I saw the oar-blade shatter as he shot.

Henderson duplicated it, selecting Harrison's right oar.

The boat slewed around.

The two remaining oars were quickly broken.