An unknown number of orcas have sunk a sailing yacht after ramming it in Moroccan waters in the Strait of Gibraltar, Spain’s maritime rescue service said on Monday, a new attack in what has become a trend in the past four years.
Archived version: https://archive.ph/PSmqu
Giant pacific octopus would be the worry I would have.
Octopus are strong and curious, if they lived longer than a few years they would be next to us or higher on the intelligence scale. They can pull off your regulator or mask just out of curiosity.
Plus their massive beaks are serious business