In Genesis, the Ark’s stated length-to-width ratio is 6:1. Genesis 6:15 gives its dimensions as 300 cubits long and 50 cubits wide, which reduces mathematically to six to one.
The ratio does not depend on knowing the exact length of a cubit because both dimensions use the same unit. The same verse gives the Ark a height of 30 cubits, producing a length-to-height ratio of 10:1.
Modern discussions often compare these proportions with those of barges or large transport vessels, because a long, broad hull can emphasize stability over speed. Such comparisons are interpretations, not proof that the biblical account describes a historically excavated ship. Genesis does not provide a curved hull profile, keel design, steering system, or detailed construction method.