The last of Bali's spectacular muck sites is about as far from the hustle and bustle of south Bali as it is possible to get. Secret Bay is located in the far northwest of the island, just outside the small town of Gilimanuk and close to the terminal for ferries that run between Bali and Java. The bay itself is quite unremarkable from the surface, with a couple of small islands, lots of mangroves and some small inlets. What makes it unusual however is the fact that cold, clear water from the deep channel that runs between Java and Bali is pushed into the narrow entrance to Secret Bay with the rising tide, bringing with it a steady supply of nutrients and plenty of planktonic eggs and larvae - probably the main reason why such a range of different species can be found at Secret Bay.
Most divers explore the northwest corner of the bay, where a small area has been built with fresh water showers and concrete troughs to rinse equipment, and a small warung that provides hot food and coffee for divers chilled by the 24-25C water that is the norm at Secret Bay. There is also a small hut where the custodians of Secret Bay can normally be found, along with a few guys that can be hired to help carry equipment down to the water's edge.
To the left of the beach at the entry point is a small jetty and beyond, a short slope from 1 - 5/6m completely covered in eel grass. Otherwise most of the area that can be reached from the beach is sand, with small patches of hard and soft corals in the shallows. The site gently slopes down to a depth of around 10-12m but is not entirely featureless like Puri Jati for example. There are small ridges, depressions and undulations along the bottom, lots of big worm casts and normally a great deal of debris, both natural and man-made, some of which has been sunk deliberately in the past. There is even a small wooden boat sunk just off the beach itself. The bottom in the deeper areas can sometimes have large amounts of lettuce-like algae and there are lots of small sponges, ascidians and hydroids growing wherever they can get a hold in the shifting sand of the bottom. There are also huge numbers of urchins in the shallows, where they gather in spiky 'rafts' during the day.
This varied terrain of Secret Bay equates to plenty of hiding places for critters and a visitor can easily spend an entire dive just exploring one small area of the site. In the eel grass bed to the north of the entry point are seahorses, unusual nudibranchs and seahares, robust ghostpipefish and normal pipefish, algal-feeding wrasse and parrotfish, gobies, camouflaged filefish and different types of juvenile fish. In the sandy shallows Banggi cardinalfish are everywhere, hiding alongside other cardinalfish species and razorfish amongst the spines of black urchins. Fingered dragonets, gurnards and gobies are easily spotted whilst mandarinfish and even the spectacular picturesque dragonet can be found at dusk. On the small wreck are clouds of cardinalfish, pipefish and catfish under the hull and banded cleaner shrimps hiding inside. A small wire frame just beyond this wreck normally has painted and other species of frogfish, lots of juveniles such as the electric-blue, black and white emperor angelfish, harlequin ghostpipefish and once again, lots of cardinals. Deeper on the sand, there are robust ghostpipefish, different species of scorpionfish including Ambon, more frogfish species such as the striated frogfish, plenty of nudibranchs and gobies, cuttlefish and octopus, sabre-tooth blennies, waspfish, pufferfish and imperials shrimps on sea cucumbers. Even seasnakes such as the elephant truck snake can make an appearance.
One of Secret Bay's most unusual residents however has to be the infamous 'Bobbit' worm. This bizarre animal - named after the unfortunate John Wayne Bobbit - is armed with a comparatively huge set of vicious jaws, designed to grasp and kill any prey, often slicing them in half in the process. They can only be found at night and are sometimes tempted out of their holes with small pieces of 'ikan Bakar' or BBQ fish bought from the nearby warung. The high chance of finding one of these incredible predators makes it worth a long, cold dive in Secret Bay!