The best snorkeling in the area is west of Nahkapw (island) along the edge of the reef, where a coral wall drops quickly off into Pahn Nahkapw‘s blue hole. Fish are abundant here and the coral is thriving. Start at the north tip of Nahkapw and follow the reef around. To the east you’ll see the massive basalt boulders that make up the island’s Nan Madol-era breakwall.
The reef walls north, west, and south of Dekehtik (island), at the northeast end of Pahn Nahkapw, offer plenty of nice underwater views and crystal-clear water. This portion of the hole is referred to as Kepindausiso –“below the noble’s channel”.
This reserve lies between Nahpali, Dekehmwahu, and Na (islands). It’s a moderately deep pool in the middle of shallow, sandy reef flats populated by a large number of stingrays (we saw more than fifteen in under an hour). You can swim out to the western edge from the southern tip of Nahpali or explore the eastern side from Na. There can be some strong currents coming from the northeast, so be alert.
Na‘s northern coast offers narrow sandy beaches and a swath of beautiful, crystal-clear water over a sandy bottom. Further out, the floor turns to beds of seagrass. There are plenty of stingrays to see in the area. When walking in the shallows, be alert and shuffle your feet to avoid potentially serious accidents.
Nahpali‘s underwater sights are all around the west side and most easily accessed from the Japanese Wharf at the edge of the reef.
The water around the northeastern perimeter of Nan Madol is usually too rough and/or murky for sub-surface exploration, but the reef pool southeast of Lemenkau can be nice on calm days and at mid to high tides. At other times, it’s either difficult to reach or has waves breaking over it.
Similar to the reserve near Na, this marine protected area consists of several deep pools in the middle of the reef shelf with sandy bottoms, good visibility, and healthy coral populations around the edge. Stingrays are abundant and reef fish diverse. The pools are a short swim from Nahnningi (island) (a.k.a. “Joy”).
Southeast of Nahnningi is a circular pool on the edge of the fringing reef. There’s a narrow opening on the ocean side that allows water and fish to flow in. Depending on the tides, this place can have amazing numbers of reef fish, but it’s too rough for snorkeling when the Northeasterlies are blowing during the winter. You can snorkel to the pool from Nahnningi.