Other Aquatic reports in Puerto Rico
2 cases, best-documented first. Page 1 of 1.
We map claims, not creatures. A case is what some source says someone saw or heard, with the link to that source. It is not proof that anything was there, and a retelling counts once, not as a second sighting.

Other Aquatic · Puerto Rico
Witness reports seeing a large, violet, translucent creature with spikes floating in the shallow water at a secluded beach in Rincón, which disappeared completely within seconds.

Other Aquatic · Puerto Rico · 1982
Two crew members on the USS Independence reported seeing an enormous shark's dorsal fin rise from the water behind the ship.