Remember when San Diego's oceans shined a fluorescent blue? Or the time a pod of killer whales swam with boaters in the waters off Sunset Cliffs? Take a look back at five times the ocean right here in San Diego wowed us in 2018:
In May, photographers captured amazing shots of a bright blue hue coming from the water just offshore San Diego's beaches.
The bioluminescent display, brought to the shore by a red tide, created by a swarm of small organisms, a type of algae, that move together through the sea.
The algae gives off the aqua glow as a natural defense mechanism from predators that try to eat the blooms, according to researchers at Scripps Institution of Oceanography.
The best time to witness the phenomenon is in the evening, in a place with no light, as the algae will not "bloom" during the daylight.
[G]Photos: Photographer Captures Pod of Orcas Swimming off San Diego Coast
A pod of orcas delighted tourists and locals alike when they swam unusually close to the San Diego coast in April, at one point visiting the La Jolla Cove frequented by sea lions.
About a half-dozen killer whales were spotted in several coastal waters in San Diego.
Incredible drone video from Instagram user dolphindronedom showed the pod of orcas surrounding and swimming underneath a small fishing boat near Sunset Cliffs, according to the photographer.
National Oceanic and Atmospheric Administration (NOAA) Marine Ecologist Bob Pitman said California's strong protection of marine wildlife may be drawing the marine mammals closer to shore, so some lucky beach-goers may be able to spot the awe-inspiring creatures in 2019 as well.
San Diego's "70 degree and sunny" disposition means trips to the beach are possible nearly year-round. Another draw to the beaches this year, though, were warmer-than-usual water temperatures.
In August, those water temperatures broke a record for the region when a monitor off Torrey Pines recorded the water at 81.3 degrees Fahrenheit.
Just days before, ocean temperatures in the waters off La Jolla broke a hundred-year-old regional record when sampled pulled from the end of the Scripps Pier showed a reading of 78.6 degrees.
It's a rare sight at San Diego's beaches: an octopus floated right up to the shoreline at Ocean Beach's dog beach earlier this month.
According to a San Diego Fire-Rescue lifeguard, octopi are not uncommon to the area, but typically they are spotted in tide pools or in the deep blue sea.
While not unique to 2018, the so-called grunion run is unique to beaches between Northern Mexico and Southern California and is always a spectacle to behold.
During the mating ritual, which happens during full moon and new moon cycles between March and August, thousands of slim, silver fish beach themselves to spawn and then return to the ocean after laying and fertilizing the eggs.