Which oceans are rougher than the Atlantic?

What ocean waters are more severe than the North and South Atlantic?

The Antarctic or Southern Ocean is worse, and the Arctic can also be, because extreme latitudes let winds and waves keep circulating around the globe.

The North and South Atlantic were demanding environments for early ocean-going ships. The Antarctic or Southern Ocean is worse, and the Arctic can also exceed Atlantic conditions. At extreme latitudes, winds and waves can continue around the globe with fewer land barriers. Surviving the Atlantic was therefore a strong design test without representing the absolute limit of ocean severity.