San Pablo Bay is a large, open saltwater bay located between Suisun Bay to the east and San Francisco Bay to the south. It offers long-distance paddling experiences with a mix of navigable sloughs and open waters. The bay is known for its significant tidal currents, which paddlers must plan around. An ebb current flowing south can reach speeds of 2 knots, providing a notable assist or hindrance depending on direction. Slack water timing can be predicted but may be influenced by freshwater inflow from rivers. The area is exposed to wind, which is a particular challenge in the spring when it "comes up." The open waters of the bay present considerable fetch, making conditions highly variable.

Several public access points facilitate exploration. Convenient boat launches are located in Vallejo, Port Sonoma, and at Hudeman Slough. Black Point on Highway 37 is another launch site, offering the option to paddle north into the Petaluma River or south into San Pablo Bay. Point San Pablo Yacht Harbor serves as a launch for trips around Point San Pablo and nearby islands like The Brothers and The Sisters. The southern shore features the Point Pinole Regional Shoreline, which offers group camping accessible mainly by water and launch points from small beaches. McInnis Park and the calm waters near China Camp State Park, a few miles from San Rafael, are also noted as favorite spots for paddlers.

The bay's environment is rich in wildlife, with the north shore's Carneros Estuary forming part of a 15,000-acre mosaic of wetlands that is a major stop along the Pacific Flyway. Paddlers may encounter significant debris in the water, including driftwood, bottles, and plastic bags, especially after storms. Water quality can be a concern following reports of raw sewage spills or significant runoff, though paddlers often assess the risk as low. The scenery includes views of landmarks like the Richmond-San Rafael Bridge, Mount Veeder, and the Carneros hills. The overall paddling experience is suited for competent paddlers due to the potential for strong currents, wind, and open water conditions, with trips often planned to coincide with favorable tides and calm weather windows.