Yeah, the OtterBox defender or armor series has the iPhone 100% totally covered. The defender is water resistant, and the armor is water proof. So if you go to beaches a lot, the armor is probably your best bet. Though I have to say that the defender is less bulky than the armor case. Either way, they'll both work really well. I live in California and I go to the beach a lot too.
I got mine from Semsons & Co. Inc. at a really good price plus free shipping. You can visit
http://semsons.blogspot.com for more information and coupon codes (who doesn't like saving money?) Just scroll down the page cause they're always updating their blog.