Jonah was suddenly confronted by the Lord and told to go to Nineveh to deliver an important message. That city was wicked and needed to be told that the Lord was against it.
Jonah fled from the presence of the Lord. At the seaport of Joppa he boarded a ship sailing for Tarshish, usually identified with Tartessus, a port on the southwest shore of Spain. Jonah did not escape the Lord. It was not the stormy season, but the Lord produced a wild storm that threatened to sink the ship.
The sailors, probably Canaanites, were polytheists and prayed to their many gods for help.
The captain found Jonah hidden below deck sound asleep. The captain wanted Jonah to pray also. If one man's god could not help, maybe some other deity could. The sailors cast lots because they believed that such a storm was caused by someone's sin. This was an opportunity for the one true God to act, so he caused the lots to identify Jonah as the sinner.
The sailors wanted to know who Jonah was and what kind of sin he had committed. Jonah confessed his faith as a Hebrew in the God of heaven, who made the sea and the land. Evidently the sailors knew about the God of the Hebrews and the miracles he had done for them. They seemed to know that running from God's presence was impossible, so they asked Jonah what kind of punishment would stop the storm.
Jonah admitted that his sin had caused the storm, and he advised the sailors to throw him into the sea. The sailors rejected the idea and, filled with fear, rowed against the raging waves with all their might.
The sailors prayed again. But this time they directed their prayers to the one true God. With great reluctance, they tossed Jonah overboard.
Whereas Jonah was disobedient and did not beseech God for mercy, the pagan sailors turned from their false deities to the true God and obeyed him. The Lord saved their lives by calming the sea. Thoroughly frightened, they worshiped God.
God saved Jonah's life by having a great fish near the boat to swallow him. Jonah remained alive and able to think seriously about his situation.