I think there were evidence roman commercial vessels were able to undertake multi-day trips across the mediterranean, say from the Aegean to Alexandrea, almost entirely out of sight of land.
It would be with roman technical capability to sail on a beam reach down Mauritanian coast of Africa to Guinea and there sail large and cross on the trade wind over to Recife in brazil. The crossing would be less than twice the distance from Aegean to Alexandrea.
As for the return journey, it takes a greater stretch of imagination, but they can sail south on a beam reach until they hit the westerlies, and there cross back to east to south Africa or nimibian coast, and there follow the easterly trade around to gulf of guinea, and then sail up on a beam reach to canaries, and there tack slightly to Portugal.
It would be with roman technical capability to sail on a beam reach down Mauritanian coast of Africa to Guinea and there sail large and cross on the trade wind over to Recife in brazil. The crossing would be less than twice the distance from Aegean to Alexandrea.
As for the return journey, it takes a greater stretch of imagination, but they can sail south on a beam reach until they hit the westerlies, and there cross back to east to south Africa or nimibian coast, and there follow the easterly trade around to gulf of guinea, and then sail up on a beam reach to canaries, and there tack slightly to Portugal.
