The moment you slip beneath the surface around El Nido, the limestone karsts that tower above you simply continue downward — submerged walls and boulders draped in soft corals and sea fans that give the whole place a slightly theatrical quality.
Visibility typically runs between 10 and 25 metres depending on season and tidal movement, and you'll find productive diving anywhere from 5 metres on the shallow reef flats to around 30 metres along the steeper wall sections near Miniloc and Helicopter Island.
Currents are generally mild, which makes El Nido more forgiving than, say, Tubbataha, but conditions vary considerably between sites. The sheltered lagoons — particularly those inside the Small and Big Lagoon systems — are ideal for snorkellers and less confident divers, with green and hawksbill turtles appearing with satisfying regularity.
If you're hunting macro, the rubble and muck zones near some of the smaller islands reward patience: nudibranchs, frogfish, and ghost pipefish turn up more often than you'd expect for a destination that's better known for its scenery than its critters.
Reef health is genuinely mixed. Some of the more accessible sites have suffered from heavy boat traffic, anchor damage, and the bleaching events that have periodically affected the Sulu Sea. The sites further out — reachable on longer day trips or through liveaboard itineraries operating out of Puerto Princesa — tend to be in noticeably better condition.
Day-boat operators are plentiful in El Nido town, ranging from highly professional to casual island-hopping outfits, so asking specifically about their buoy mooring practice before you book is worth doing.
Best visited between November and May; open-water certification covers most sites, though stronger swimmers will get more from the exposed wall dives.