Boys will do that.

The captain tried to keep me from going in again, but I knew it was all nonsense to be frightened.

I was going to bring up something from the bottom, if it was only a pebble.
So, after resting a little while, and getting my breath again, down I went.

I was in for anything now, and the moment I reached the bottom, I swept my arm around and seized the first thing I touched.

It was a pretty big thing, for it was a sea-feather over five feet high,--a regular tree.