Which sentence is punctuated correctly?

De Vaca was a Spanish explorer, he was shipwrecked in 1528, on what is now Follets Island.

De Vaca was a Spanish explorer; he was shipwrecked in 1528 on what is now Follets Island.

De Vaca was a Spanish explorer, he was shipwrecked in 1528 on what is now Follets Island.

The sentence "De Vaca was a Spanish explorer; he was shipwrecked in 1528 on what is now Follets Island." is punctuated correctly.