Assuming you could figure out a way to explore the bottom of the area without any surface support (ie, long range submarine), you would probably still be lucky to find an intact wreck site due to the currents and ocean floor topography. Just my assumption. But I'm sure the bottom is littered with wreckage from the 16th century on up. Very intriguing question that has been on my mind as well!!
Cape Horn (and Strait of Magellan) in southern Chile are known for their extremely difficult navigation. Water is very cold and deep. As it was stated earlier currents are strong and will test the best navigators. Punta Arenas is the main city port along the Strait.