The answer is: They made sacrifices to God

Jonah 1:16 - They probably became true converts to the God of Israel.

Once the storm had passed and the chaos subsided, the ship's crew found themselves filled with awe and gratitude. After all, they had just survived what felt like a cataclysmic encounter with nature—one that displayed divine power in a way they had never experienced before. In every ancient culture, turning to gods through offerings was common practice, and the crew of Jonah's ship did just that. They made sacrifices to God, transforming a moment of danger into one of spiritual awakening.

This act wasn't merely ritualistic; it suggests a heartfelt response to the recognition of a greater truth. It points to a fascinating element often noticed in the Bible: the unexpected spread of faith beyond Israel's borders, whereby non-Israels find themselves drawn into the divine narrative. Comparatively, if you want to see a similar theme, look at Jesus’s interaction with the centurion or the Samaritan woman—even the message often touched lives beyond conventional lines.

Interestingly, some traditional interpretations imply these mariners became true converts to the God of Israel. Though they started as just everyday sailors, they left the experience transformed; enlightenment often arises amidst turmoil. In a world that feels rough at times, this passage showcases how adversity can lead to profound recognitions about faith—planting seeds of spiritual curiosity outside of expected bounds, and illustrating a God that’s just as interested in everyone in the boat as the one thinking about jumping overboard!