John Calvin on Jonah 1:15

Jonah shows here that the tempest arose through his fault; for the issue proved this with certainty. The sailors had not only cast lots, but after Jonah was thrown into the sea the storm calmed, and the sea became still, — this sudden change sufficiently proved that Jonah was the only cause why they were so nearly shipwrecked. For if the sea had not calmed immediately, but after some interval of time, it might have been ascribed to chance: but as the sea instantly rested, it could not be otherwise said than that Jonah was condemned by the judgment of God. He was indeed cast into the sea by the hands of men; but God so presided, that nothing could be ascribed to men, but that they executed the judgment which the Lord had openly demanded and required from them. This, then, is the import of this verse. He now adds —

Jonah 1:16

16. Then the men feared the Lord exceedingly, and offered a sacrifice unto the Lord, and made vows.

16. Et imuerunt viri timore magno Jehovam, et sacrificarunt sacrificium Jehovae, et voverunt vota.