The Watugo was a tribe whose lands were across the Great Water (South Lake) from the Vashta. The Watugo were a seafaring community who developed the technology for large ships that enabled trade between long isolated tribes. They were also artisans who crafted the famous Watugo pottery, a few of which still remain in existence today.
With the invention of these great ships, new trade avenues were opened between tribes on totally separate continents who had never been in contact with each other before that time.
This also resulted in the spreading of germs among groups who had developed no natural immunities to them, bringing about the Great Sickness that nearly eradicated all animal life from the planet.
To read more about the Watugo and the Great Sickness, consult the Elder Scrolls.