Singing...California Sea Lion (Zalophus californianus)? Approaching at speeds up to 20 mph this sea lion was caught in the act of expelling bubbles into my facemask as a playful gesture at Los Islotes. This is perhaps the way that the sea lion imitates the exhalation exhaust from the second stage of my regulator. This mammal has been known to dive to depths of 450 feet and stay underwater for up to 20 minutes. These cute, inquisitive animals were once heavily slaughtered in the 1800's for their meat and oil. Luckily the human race has curtailed this practice and numbers of sea lions have been steadily increasing; however, many are now being inadvertently caught in nets by commercial and sport fisherman. Hopefully as technology increases, better fishing methods will be developed to reduce unwanted by-catch including the California Sea Lion.