Remember that the drop out rate is above 70%, and is higher in the winter months. I have spent time in Coronado, and it suck there. I took the SEAL indoc a while ago, when they were offering $40,000 enlistment bonus upon completing BUDS, still think about it sometime. But consider this, just because you don't quit doesn't mean you will make it. You can get med rolled, or dropped for failure to adapt. Practice running in the sand, because you can be a great runner on the pavement, but the sand will change that all together, it makes your lungs burn like crazy.
Here is some of the fun stuff you get to do.
http://www.youtube.com/watch?v=1lsc_X7ls8o