וַיִּֽירְא֣וּ הַמַּלָּחִ֗ים וַֽיִּזְעֲקוּ֮ אִ֣ישׁ אֶל־אֱלֹהָיו֒ וַיָּטִ֨לוּ אֶת־הַכֵּלִ֜ים אֲשֶׁ֤ר בָּֽאֳנִיָּה֙ אֶל־הַיָּ֔ם לְהָקֵ֖ל מֵֽעֲלֵיהֶ֑ם וְיוֹנָ֗ה יָרַד֙ אֶל־יַרְכְּתֵ֣י הַסְּפִינָ֔ה וַיִּשְׁכַּ֖ב וַיֵּרָדַֽם׃
And the mariners were afraid, and cried every man unto his god; and they cast forth the wares that were in the ship into the sea, to lighten it unto them. But Jonah was gone down into the innermost parts of the ship; and he lay, and was fast asleep.
Rashi on Jonah
each one... to his god—Of the seventy nations of the heathens were there.
Ibn Ezra on Jonah
He lay down and slept - from seasickness, and perhaps this was his first time on a ship.