The San Francisco Bay Trail boat ramp in Oakland, California is a public boat launch ramp located at the Martin Luther King Jr. Regional Shoreline Park. It is a concrete ramp that provides access to the San Francisco Bay. The ramp is approximately 20 feet wide and is suitable for launching small boats, canoes, and kayaks.

According to the official website of the East Bay Regional Park District, which manages the Martin Luther King Jr. Regional Shoreline Park, the boat ramp is currently open from dawn to dusk. The website also states that the park is open for day use only, and overnight camping is not allowed.

As for the type of watercraft permitted on the water, the website states that "non-motorized boats are generally allowed in the park," including canoes, kayaks, and rowboats. However, motorized boats are not allowed within the park except for authorized vessels used for park operations and emergencies.

In summary, the San Francisco Bay Trail boat ramp in Oakland, California is a public concrete ramp that provides access to the San Francisco Bay. It is approximately 20 feet wide and suitable for small boats, canoes, and kayaks. The ramp is located within the Martin Luther King Jr. Regional Shoreline Park, which allows non-motorized boats such as canoes, kayaks, and rowboats on the water.