Leo folded a paper boat, but this one had a porthole and a little periscope.

He carried it down to the harbor and set it gently on the green water.

Under the waves, the little sub drifted past seaweed and a rusty anchor.

Leo drew a map: where the jellyfish danced and where the rocks hid.

A friendly turtle swam beside the sub and smiled through the porthole.

When Leo brought his submarine home, he pinned the map on his wall.