That sounds like it was quite an exciting encounter. I'm actually not familiar with the jellyfish around here, but from your description it sounds like it could have been Chrysaora fuscescens, also known as the Pacific sea nettle. It's said to be off the California coast, with a body that can reach 3 feet in diameter (though most are about 1.5 feet), and tentacles that can be 12 to 15 feet long (!). From pictures I saw, it looks brown/tan in coloring. Here's some information on it:
Chrysaora_fuscescens

If that doesn't sound like what you saw, we have many knowledgeable faculty at UCSB in the marine biology department who may have a much better answer.