the World Pond

The World Pond is what the Slann and other Lizardmen call what the Old Worlder's usually call "the Great Ocean".
The World Pond is roughly analagous to the Atlantic Ocean in the real world but most geographic features in the Warhammer world are roughly twice as large in the Warhammer world as in the real world.
While it's a long a perilous sea voyage across the World Pond and supposedly a lot of ships who attempt the trek never make it, in both official and unofficial WHF stories, a ships likelihood of surviving the journey depends on the needs of the plots.
Also for some reason it seems to be very rare for ships to fail the journey when traveling from Lustria to the Old World, only when traversing the World Pond the other way.
It is a fantasy ocean so there are sea monsters present, but sea monsters only seem to frequent certain areas, and more often than not sailors have to worry about inclement weather or running out of supplies more than they have to worry about kraken and leviathans.

Type

Ocean