Hampton Beach is actually "Hampton State Beach Reservation". They are one and the same.
Metal detecting IS ALLOWED and many of us go there all the time to detect and have no problems at all.
Parking is $2/hour in the state run lots (right along the beach) and is in effect from 8am-midnight/7 days per week. They WILL ticket you if you do not pay for parking or your time limit has expired (you can keep adding time). There are also many pay lots ranging in price from $10-$30 per day. On street parking is available but very hard to find especially on weekend days. If you have handicapped plates/placard you can park for free in any legally marked parking spot.
There are 3 bathrooms along the beach, opening I believe around 8am and the main one closes around midnight (others close around 10:00). Also outdoor showers to rinse off your scoop and machine.
Check out the Hampton Beach WebCam to see the crowds on the beach.
Hampton Beach, New Hampshire - The Premier Vacation Spot on the NH Seacoast and a Whole Lot More!
Just a note: September 6, 7 & 8, 2013 is the annual Seafood Festival at the beach. Parking is an absolute B***H during this event = (non-existent. Most people park at remote areas and take a shuttle bus to the beach). Wall to wall people on Ocean Avenue (no parking allowed in the state run beach lots) and no vehicular traffic allowed. (Ocean Ave is closed off to traffic). Don't know how busy the beach is during this festival as we tend to avoid Hampton during it. Fireworks are scheduled for September 1 (9:30pm) and September 7 (8:15pm). I believe there is a fee to get into the festival and you pay for the seafood.
Lots of restaurants (can be pricey) and shops along the main drag. Motels and hotels along the beach can be very expensive, too. If you stay away from the beach, rates drop. There is also a state run campground (wide open RV spots with no shade at all) right on the beach.
PM me if I can be of further help. Hampton is well hunted by many of us. My husband and I started off the season very strongly (3 gold rings) there, but the beach is now very sanded in (both dry sand and in the water) and aside from daily change drops, very quiet (at least to my husband and I). You will also find lots of pull tabs and bottle caps on this beach, but it is a nice beach to hunt. It is over a mile long and very well maintained
Hope you enjoy your vacation! Remember, too, there is no sales tax in NH. (There is a meal tax and hotel tax, though.)
Anita