Why was control of the Gulf of Mexico important to Spain?

The Gulf of Mexico (Spanish: Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North Americancontinent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. The U. S. states of Texas, Louisiana, Mississippi, Alabama, and Florida border the Gulf on the north, which are often referred to as the "Third Coast", in comparison with the U. S. Atlantic and Pacific coasts.

Explanation: The control of the Gulf of Mexico was important for Spain because it was a vast area of deposits of different minerals, (especially silver), and a fruitful agricultural region. For this reason, Spain intended to establish colonizations on the northern coast of the gulf in order to provide protection to merchant and expeditionary vessels and also quickly rescue the shipwrecked.