Underwater Parks Day is an annual celebration of California's marine protected areas (MPAs), the network of "underwater parks" that runs along the state's coast. Each January, aquariums and science centers across Southern California host family-friendly events where divers, snorkelers and anyone curious about the ocean can meet the scientists and conservation groups who study these areas. This guide from the DiveCatalog team covers what Underwater Parks Day is, the facts behind California's MPA network, where the celebration has been held, and how divers can take part.
What Is Underwater Parks Day?
The Aquarium of the Pacific sums up the idea simply: "Just like there are parks on land, there are also parks underwater." Underwater Parks Day is a statewide celebration that raises awareness of those underwater parks, which are California's marine protected areas. The Santa Barbara Museum of Natural History notes that the day is celebrated in partnership with aquariums and science centers across Southern California, with each host running its own program of booths, talks and hands-on activities.
For local divers and dive clubs, it is an easy way to spend a winter Saturday with other ocean people, learn where the protected areas near your favorite sites begin and end, and connect with volunteer programs that monitor them.
California's Underwater Parks by the Numbers
According to the California Ocean Protection Council, California completed a science-based, stakeholder-driven process in 2012 to designate a network of 124 marine protected areas covering about 16% of state waters. The California Department of Fish and Wildlife (CDFW) describes it as "the largest ecologically connected network in the world." CDFW's published statistics break the network down further:
- 124 protected areas statewide: 119 MPAs plus 5 state marine recreational management areas, along with 14 special closures.
- About 852 square miles in total, or 16.12% of coastal state waters (excluding San Francisco Bay).
- 49 State Marine Reserves, covering 8.76% of state waters.
- In the Southern California region alone, 50 protected areas covering about 15% of the region's state waters.
Reserves vs. Conservation Areas
Not every MPA has the same rules. In a State Marine Reserve (SMR), take of all living marine resources is prohibited. State Marine Conservation Areas (SMCAs) may allow some recreational or commercial take, depending on the regulations for that specific area, and a small number of SMCAs are designated no-take. Because the rules differ from one MPA to the next, CDFW publishes maps and the regulations for each area. If you dive, snorkel or spearfish along the coast, checking CDFW's MPA maps before a dive is the reliable way to know which rules apply where you are going.
Where Underwater Parks Day Has Been Celebrated
Host venues and programs change from year to year, so treat the list below as a guide to where to look rather than a schedule.
Sea Center on Stearns Wharf, Santa Barbara
The Santa Barbara Museum of Natural History Sea Center has made Underwater Parks Day a regular event. The 2025 celebration took place on Saturday, January 18, 2025, and the 2026 celebration on Saturday, January 17, 2026, with all-day free admission from 10:00 AM to 5:00 PM and festival partners on site until 3:00 PM. The museum listed 2026 partners that included the Spotting Giant Sea Bass project, Santa Barbara Channelkeeper, Heal the Ocean, the Channel Island Naturalist Corps, Channel Islands National Marine Sanctuary, Chumash Heritage National Marine Sanctuary, the Blue Whales Blue Skies program and the Caselle Lab at UC Santa Barbara.
Aquarium of the Pacific, Long Beach
The Aquarium of the Pacific has hosted Underwater Parks Day as a chance to "learn more about Southern California's network of Marine Protected Areas (MPAs)." The aquarium listed the event as included with general admission.
Cabrillo Marine Aquarium, San Pedro
Cabrillo Marine Aquarium has also joined the celebration, with past programs that included talks and presentations, hands-on activities and handouts about how MPAs work and where they are located in Southern California.
When Is Underwater Parks Day 2027?
As of this writing, host venues have not announced their 2027 dates. Recent celebrations have been held on a Saturday in mid-January, so the event calendars of the Sea Center, the Aquarium of the Pacific and Cabrillo Marine Aquarium are the best places to watch in December and early January. If your dive club wants to attend as a group, those calendars will also list hours, admission details and any reservation requirements.
Ways Divers and Snorkelers Can Take Part
Underwater Parks Day is centered on events ashore, but the parks themselves are open to visit year-round. Here are a few ways the local dive community can get involved.
Visit an MPA and Look, Don't Take
Many popular Southern California shore and boat dive sites sit inside or next to MPAs. Visiting an MPA, and respecting its rules, is one of the simplest ways to celebrate. Many divers and snorkelers bring a camera so they can take home photos and video instead of anything from the reef. Our compact underwater cameras include sealed models that need no separate housing.
A permanently sealed compact camera with a 16MP Sony sensor, 4K video at 30fps and 64GB of internal memory. SeaLife depth tests each camera to 200 feet (60 m).
Snorkeling is another low-key way to see an underwater park, especially for friends and family members who are not certified divers. You can browse mask, snorkel and fin options in our snorkeling collection.
Tusa Tri-Ex Dive Mask and Snorkel Combo (UM-31/USP-250)
Pairs the UM-31 three-window mask, which Tusa rates for a 168-degree panoramic view, with the USP-250 snorkel and its Hyperdry Elite dry top. Both pieces use pure silicone where they touch the face.
Join MPA Watch
MPA Watch is a volunteer program that monitors California's coastal MPAs. Volunteers record activities they observe inside and outside protected areas, such as swimming, surfing, fishing and harvesting, and the data is quality-checked before state coastal managers and researchers use it. MPA Watch lists several ways to help: completing surveys, volunteering with a local program, donating to local MPA Watch organizations and visiting MPAs. If you want more volunteer options, our guide to becoming a citizen science diver covers programs open to certified divers.
Make It a Club Outing
Underwater Parks Day events are family-friendly and held ashore, so they work well as a club social that includes non-diving partners and kids. Pairing the event with a club dive or snorkel at a nearby MPA on another weekend is a natural follow-up. To learn more about the habitats many of these parks protect, read our guide to California's kelp forests and what lives below.
Questions
Event details, dates and admission are set by each host venue, so check their calendars for the latest information. For questions about the products mentioned in this post, email the DiveCatalog team at support@divecatalog.com.
Sources: California Department of Fish and Wildlife MPA statistics; California Ocean Protection Council MPA network overview; Santa Barbara Museum of Natural History press releases (2025 and 2026); Aquarium of the Pacific; Cabrillo Marine Aquarium; MPA Watch. Product specifications from SeaLife and Tusa.
