Starting with Common Dolphins, the Fastest Marine Mammal on Earth
Common dolphins are typically the first common marine mammals we see offshore San Diego. True to their names, thousands of these energetic dolphins constantly patrol the Pacific Ocean off our shores. That being said, these tiny speedsters only account for a small portion of the dolphin diversity San Diego has to offer. We often see both short-beak (Delphinus delphus) and long-beak (Delphinus capensis) on our trips. The short-beaks are the smallest and fastest at just 5-6 feet long, while the long-beaks are larger, at 6-8 feet long. There’s some debate as to whether they qualify as separate species, but the long-beak’s striking looks and typical eye-shadow distinguish them pretty clearly for us!
Bottlenose Dolphins: Near Coastal to Offshore
Moving up in size, we often have bottlenose dolphins (Tursiops truncatus) regularly make their first appearance right inside of Mission Bay! They are social creatures, and tend to form close-knit family bonds with their pods. While often friendly to boats, a careful approach is ideal for these near-shore denizens, as they may shy away after a day of heavy boat traffic.
Offshore bottlenose dolphins may be the same species as their coast-hugging neighbors, but they differ in noticable ways.They are typically 15-20% larger and darker than their nearshore cousins, and can be quite acrobatic. Like their near shore counterparts, they form supportive and intimate families. We’ve seen even seriously injured individuals with damaged noses and missing fins go on to survive and thrive without issue! As a group, we’ve seen them work together to support all members of the pack. In this way, even dolphins greviously injured by orca attacks can go on to be thriving members of their pack.
Risso’s Dolphins: Big and Battle-Scarred
Risso’s Dolphins (Grampus griseus) are the typically the next largest dolphins we see locally. Risso dolphins are characterized by their striking white-scarred skin. Their natural color is usually dark gray, but a life of constant deep-water hunting and rough-housing leave their bodies decorated in a maze of interweaving streaked scars.
Risso’s dolphins are known for being able to dive thousands of feet deep in search of some of their favorite prey, squid! In particular, the Humboldt squid can use vicious sharp beaked mouths to scrawl deep grooves in the bodies of Risso’s dolphins. Teamwork and thick blubber protect these dolphins, allowing them to rip into daunting prey without worry.
Orcas: The largest and most powerful of the Dolphin Family
Not even Risso’s dolphins can compete with the largest dolphin, the Orca (Orcinus orca). While their common name of Killer Whale would suggest otherwise, they are in fact members of the dolphin (Delphinidae) family. Orcas are apex predators in every sense of the term, and every trip they make to San Diego is electrifying. Those that visit us come from the Eastern Tropical Pacific Pod, a group that usually makes its home in Baja California, Mexico, and they specialize in hunting both dolphins and whales.
Orcas don’t have an offical season for us in San Diego, but 2023-2025 has seen the eastern tropical pod visit us consistently right around Christmas through March! If you’re willing to try your luck, come join us for a dolphin-watching adventure!