You're kidding aren't you? Beer in a backpack? Not the ideal backpackers beverage, bulky, weighty, and trash to carry out. We brought a six pack for our day at the beach. Hey! We were in College! Lake Superior makes a good fridge for cooling them down after several days in the pack. I recommend a mest bag (available at your local dive shop) then toss them into the lake with a line attached that you can stake on the beach. Pictured Rocks is an easy hike so we didn't mind the extra weight, hey we even brought a couple of bottles of wine!! Just make sure you carry your trash out!!
While planning the hike, I noticed that several days in we would camp on the beach, so I asked everyone to bring wild clothes, for a beach party. On the way up, we stopped at a winery, and got several bottles that we had to carry in our packs for several days. It was worth the effort.
Dress Code: Hawaiin shirts, or Bermuda shorts are the order of the day. Or something equally as loud. Preferably loose fitting, and heavily patterned.