Dive Site: Sunken Island

About Sunken Island

Sunken Island is a distinguished dive site located off Siquijor, an island in the Visayas region of the Philippines, south of Cebu and Bohol. This site is a true geological marvel, an underwater island where the top plateau begins at a depth of 10 to 15 meters and plunges dramatically to around 40 meters, creating a diverse and captivating underwater landscape. The topography features impressive walls adorned with a profusion of soft and hard corals, whip corals, and sponges that create a vibrant, living ecosystem. Marine life here is abundant and varied, showcasing the rich biodiversity of the Philippines. Divers can expect to encounter an array of reef fish, jack fish, and numerous sea snakes and turtles, with reports of exceptionally large turtles inhabiting these waters. While the site does not host thresher sharks, like some other 'Sunken Island' named sites, it offers its own unique pelagic encounters and macro opportunities. The pristine condition of the corals and the sheer volume of fish life contribute to an exceptional diving experience. Siquijor itself is known for healthy coral reefs and a great variety of macro critters, ensuring consistent marine observations. Diving Sunken Island is considered an advanced experience due to potentially strong currents. Divers must be prepared for a quick descent upon arrival to avoid being swept away. This challenge, however, is well-rewarded for experienced divers, offering a thrilling exploration of deep walls and vast coral formations. The best time for diving in the broader Siquijor area, which experiences generally easy-to-beginner friendly conditions in other sites, largely mirrors the optimal conditions across the Visayas, with consistent diving available year-round, though calmer seas and best visibility often fall between January and June.

Dive site facts: Sunken Island

Depth

20–40 m

Current

Mild

Visibility

10–25 m

Water temperature

27–30°C

Entry

Boat dive

Level

AOW recommended, drift experience helpful

Dive type

Reef, wall, shark dive

Region / port

Visayas

Coordinates

11.31, 124.205

Conditions & Currents

Currents at Sunken Island are generally mild, yet divers should be prepared for varying conditions, especially around the exposed seamount. Dive operators monitor tides closely, and briefings will cover specific entry and exit procedures, as well as potential drift. While not typically a high-current environment, some drift diving experience is beneficial to navigate the site comfortably. Visibility can range from 10 to 25 meters, influenced by currents and plankton blooms that also attract larger marine life. Divers should plan their gas consumption conservatively, considering the average depth of 40 meters.

Marine life & sighting chances

Thresher sharks

Year-round, early morning · common

Manta rays

Year-round, full moon · occasional

Pygmy seahorses

occasional

Nudibranchs

common

Mantis shrimps

occasional

Reef sharks

occasional

Tuna

occasional

Groupers

common

Barracudas

occasional

Corals

common

Reef fish

common

Dive profile & how the dive runs

Dives at Sunken Island typically begin with a boat entry, followed by a descent to the top of the seamount around 20 meters. From there, divers explore the cleaning station, keeping an eye out for thresher sharks in the early morning. The dive progresses along the slopes and walls, which extend to depths of 40 meters, showcasing diverse coral formations and macro life. Depending on current conditions, the dive might be a drift along one side of the island before turning back. The safety stop is usually conducted in the shallower sections of the seamount, offering opportunities to observe smaller reef fish before a boat pick-up.

Underwater photography

Sunken Island offers fantastic opportunities for both wide-angle and macro photography. For pelagic encounters like thresher sharks and manta rays, a wide-angle lens is essential, preferably with external strobes to bring out color in deeper water. Early morning dives increase the chances of capturing these subjects. For macro enthusiasts, a dedicated macro lens will reveal pygmy seahorses, nudibranchs, and mantis shrimps hidden among the corals and sandy patches. Patience and excellent buoyancy control are crucial to avoid disturbing delicate subjects and maintain good composition, especially with potential currents. A focus light can be very helpful for macro subjects.

Combine with nearby dive sites

• Monad Shoal

  Another renowned thresher shark cleaning station, also a sunken island.

• Apo Island

  Famous for its marine sanctuary, diverse corals, and abundant turtle sightings.

• Moalboal Sardine Run

  Iconic site known for massive sardine bait balls and pelagic action.

Getting there & logistics

Access to Sunken Island is typically arranged through dive resorts and operators in the Visayas region, often from islands like Malapascua, Cebu, or Siquijor. Major international airports include Mactan-Cebu International Airport (CEB) or Manila Ninoy Aquino International Airport (MNL), with subsequent domestic flights or ferry transfers. Dive trips usually involve daily boat excursions from local dive centers. No specific park fees are mentioned for Sunken Island itself, but local dive packages will incorporate boat costs and guide services. It's often combined with other dives in the vicinity on a multi-day itinerary.

Safety & environment

Divers at Sunken Island should hold an Advanced Open Water certification due to the maximum depth of 40 meters. Always dive with a reputable local operator and follow their briefings concerning currents, which, while generally mild, can vary. Plan your dive within no-decompression limits and monitor your air consumption carefully. Emergency medical facilities and recompression chambers are limited in remote areas of the Philippines; the nearest recompression chambers are typically located in larger cities like Cebu. It is highly recommended to have comprehensive dive insurance that covers emergency evacuation and medical treatment. Always carry an SMB for surface signaling, especially in areas with potential drift or boat traffic.

Who it suits — and who it doesn't

FAQ

Sunken Island FAQ

Liveaboards diving Sunken Island

These liveaboards may visit Sunken Island on selected itineraries — the exact dive sites depend on departure, weather and conditions.

Infiniti

Philippines

25 guests39 m

$280/day

Seadoors

Philippines

16 guests25 m

$335/day

Resolute

Philippines

16 guests34.6 m

$314/day

Dolphin

Philippines

18 guests31 m

$326/day

Navis 1

Philippines

22 guests23 m

$250/day

Philippine Siren

Philippines

16 guests

$309/day

Palau Sport

Philippines

24 guests38.35 m

$215/day

Philippines Aggressor

Philippines

26 guests42.7 m

$381/day

Stella Maris Explorer

Philippines

20 guests33 m

$398/day

Solitude One

Philippines

24 guests52 m

$460/day

Atlantis Adventurer

Philippines

16 guests32.5 m

$421/day

Philippines Aggressor II

Philippines

26 guests42.7 m

$247/day