[potato3732842]

>As a layman, considering the technology at the time, it does not sound so much more wider.

Think about the lever arm of that "other half meter" of ship that you're dragging up into the air when you heel the ship over plus the increased displacement of the half meter you're burying into the water.

Remember, ships aren't really subject to huge propulsive forces relative to their mass compared to land vehicles. So something like an extra meter is gonna make a pretty big difference.