I know it is a little late to post on this but my family and I would not recommend Powderhorn for a quiet stay. My son, daughter-in-law and new 4 month grandson stayed there with us this summer (2004) and the noise and rudness was horrible. The place is a zoo to say the least. I suggest reading the campground reviews for Powderhorn before staying there. The other campground Wild Acres owned by the same people would be the same situation. Overcrowded and the customer is always wrong.
****News**** The owners of Powderhorn recently purchased Hid'n Pines.
Our suggestion is to find a campground on the outskirts of Old Orchard and make the drive. You won't be hit with overinflated charges to stay and will help to offset the parking fees downtown in Old Orchard Beach. As far as the ocean, we also suggest for a nice day at the beach itself would be to visit one of the smaller nearby beaches instead. The boulevard is nice at Old Orchard but the crowds aren't that great for young families with small children all of the time.
My brother-in-law and sister-in-law swear by Baileys but they are very expensive and you pay for everything.