Mission Bay

Mission Bay Park covers 4,235 acres in San Diego, a little over half of it water, and it is the largest man-made aquatic park in the United States. The bay opens to the Pacific through a narrow entrance channel between Mission Beach and Ocean Beach, and city parks close it on the other 3 sides. Crown Point Shores, Vacation Isle, Fiesta Island, and De Anza Cove are the major named areas inside the bay, and SeaWorld sits on the south shore. Open-ocean swell does not reach the interior in any season.

Reduced wave energy and gentle tidal exchange through the narrow ocean channel keep Mission Bay in the bay biome. The bay also supports a seagrass biome, with eelgrass beds spread across the shallow sand flats.

Hook-and-line fishing for halibut on the channel drifts is the most common water activity, and swimming and wading are common at the designated swim beaches. No swell reaches inside the bay, so surfing is absent, and consistently low visibility (rarely above 10 feet) keeps scuba uncommon and limits snorkeling to the calmer corners.

Free public lots serve the bay parks at Crown Point, Fiesta Island, De Anza Cove, Vacation Isle, and Bonita Cove. Lots fill quickly on summer weekends, but the bay is large enough that a spot can usually be found somewhere. San Diego Municipal Code section 63.20.18 makes it unlawful to carry a cocked or armed fishing spear gun in any public swimming area or within 50 feet of a swimmer, and the city closes the Mission Bay entrance channel to swimming and diving. Outside those limits, fishing and spearfishing follow standard California regulations, though heavy boat, jet ski, and swimmer traffic combined with the low visibility make the bay a poor place to dive.