1:15 - So they picked up Jonah, threw him into the sea, and the sea stopped its raging.
Cause and effect. The lot called out Jonah as the cause of the storm, and Jonah's words in v. 12 predicted the effect of throwing him overboard.
An interesting note: Jonah never speaks falsely. He never tries to hide who he is, what he is doing, what he thinks (revealed later). He is the ultimate hypocrite, though as he says and believes one thing while acting differently.
1:16 - Then the men feared the Lord greatly, and they offered a sacrifice to the Lord and made vows.
Salvation has come to the ship! The sailors:
1. Feared the one and only God rightly.
2. Offered a sacrifice to the Lord.
3. Made vows (to the Lord, it is assumed).
Unlike the unrepentant prophet, the sailors respond to the discipline of the Lord. It is ironic that Jonah refused to go to Nineveh to take the word of the Lord to the city of pagans, but he ends up exposing the pagans of the ship to the word of the Lord and bringing a sort of salvation to them.
The original audience would rightly recognize the repentance of the sailors in the face of Almighty God and would have felt even more justified at Jonah's refusal to go to Nineveh. If God would save ungodly pagan Gentile sailors, He would do the same and more for the ungodly Gentile Ninevites.