St. Francis of Paola Crosses the Strait of Messina
Convento di Fuligno, Florence, Italy
This episode is recounted in the Historia Supplementum assembled by Daniele Papebrochio in the Acta Sanctorum's article on this saint (April vol. 1, 201). This particular image shows other vessels in the water, but in the account Francis has to rely on this miraculous mode of travel because there are no sailors available: the waters were especially turbulent, and many had been lost to famine.
The account does not mention a fellow traveler, but most images include one.
Read more about St. Francis of Paola.
Source: Wikimedia Commons