Map of Marine Protected Areas of American Samoa
The coordinates shown for all tentative sites were produced as a community effort. They are not official and may change on inscription.
American Samoa contains super lush green volcano mountains and several parts are protected by the National Park of American Samoa. They work closely together with the National Marine Sanctuary unit. Both organizations have great offices in Pago Pago and you should check them out to get more info on hikes and snorkel/dive trips.
From what I gather the protected marine sanctuaries are six parts. The easiest access to these is given at Fagatele Bay. You need to ask for permission to hike there because the land is owned by a local family. The trail will lead to the bay and weather permitting it enables you to snorkel and swim at a small beach. You can also scuba dive in this and the adjacent protected Larsen Bay. Similarly you can go the nearby island of Aunu'u for more of the same. Getting there is only done by a short boat ride for day trips.
Many think of American Samoa's highlight as being the beach at Ofu. Getting there is not as tricky as expected but the timing has to be done right. There are boats around twice a week and a flight once a week. With a combination of these you wouldn't need to spend a whole week enjoying the pristine beach at Ofu. There are no sanctuaries on lovely Ofu but the nearby island of Ta'u has a wonderful so-called "Valley of the Giants" which makes it a great diving spot. This needs to be arranged on Ta'u itself which is reachable by the ferry island hopper or by plane.
Another place that are protected include the pearl heaven of Rose Atoll - probably the top reason this should be a World Heritage Site. The researchers make a trip here once a month or so for checking the birds and corals. The area is off limits to the public.
Lastly there is Swains Island. This is the problem with the proposed sites as it is currently under dispute with Tokelau for ownership. Tokelauens regularly visit the island for cutting down coconuts and the rangers confirmed they hardly make any trips up there due to the distance.
One of the natural hazards to the sites are the spread of Crown-of-Thorns in the warm waters. With global warming come the sped up breeding of these starfish which destroy the corals. You can spot these when snorkeling in slightly deeper waters already and keeping their numbers in check is unfortunately a painful manual task. Do not be surprised if your dive master starts killing one of these during a dive or even brings along an injection gun.
The site has 6 locations