open water swim lessons in san francisco south bay area

Hi.

I have signed up for my first triathlon in september but I have no experience in open water especially ocean.

Where can I practice/take lessons for open water swimming in san francisco south bay area. I have never been in open water. I'm looking for a clinic or a class where they provide help in case of emergency. I found http://www.odysseyopenwater.com/berkeley.htmlbut they are in north bay and very far from my place. I have also signed up for https://runsignup.com/Race/Events/CA/SantaCruz/OpenWaterSwimClinic#e... but it is still 20 days away.

Any recommendation is highly appreciated.