Ambrósio is Santa Maria's signature offshore reserve, a compact seamount in blue water where mobula rays, jacks, barracuda, tuna, and other pelagics gather through the warm-season run. Most dives focus on staying close to the line above the reef and letting the action come to you rather than touring a sheltered reef edge. The site is reached by boat from Vila do Porto and feels exposed to Atlantic conditions, so days are built around weather, current, and skipper judgment. When it settles, Ambrósio delivers one of the island's most reliable big-animal experiences and can also suit confident snorkellers hoping to watch mobulas pass in the upper water column.