30 degrees north and 90 degrees west is located in the Gulf of Mexico, specifically in the western part of the Gulf Stream.

Here's why:

* Latitude: 30 degrees north is a line that runs through the southern US, northern Mexico, and North Africa.

* Longitude: 90 degrees west is a line that runs through the central US and the Gulf of Mexico.

This specific location is a bit south of the US state of Louisiana and east of Texas. It's in the middle of the Gulf Stream, a strong ocean current that moves warm water northward from the tropics.