There are ways to get campsite some of you may not know.
It's a little known secret the park service won't tell you about but does nothing to stop it. 10 day max stay, reserve 5 months in advance, $7 processing fee. You'll be there for 3 nights, reserve for 10 with the last nights being the one's you really want. Wait awhile and cancell the earlier 7 nights ($7 fee). This gives you a 7 day jump on the rest of the campers who are trying to reserve those wanted 3 days. The cancellation fee is only the $7 processing fee.
By doing this you can get the beach front sites. The only bug is taht someone may not be leaving when you your 10 days window opens, you then try for 9 the next day and 8 the day after. This works and is being used by the savy campers.