At the time of pangaea, essentially all of the major landmasses on the planet would have been connected together, which also means all of the waters of the oceans would have essentially constituted one large body. what was this giant ocean called?

Panthalassic Ocean

Explanation:

During the time at which the last super-continent Pangaea existed, there was an enormous ocean as well. This ocean was stretching from one side of Pangaea to the other side of it, circling the rest of the planet that was not covered with land. The name that was given to this ocean is the Panthalassic Ocean. It has to be mentioned though that it was not the only ocean during this time though, as there were two other much smaller oceans, the Paleo Tethys Ocean and the Tethys Ocean, both being located between the land masses that later gave birth to Eurasia and Australia. Because of the size of the Panthalassic Ocean it was capable of producing much stronger storms and waves that the human kind had ever witnessed, and it is certain that those storms and waves were doing enormous damage along the coastline of Pangaea.