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Our Survey Sites

ReefX Expedition

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Pulau Hantu

Pulau Hantu, known in local folklore as Ghost Island, is located in the southern shores of Singapore. Accessible by a thirty-minute boat ride, the island is a favourite with macro photographers.


Pulau Hantu hosts an abundant array of marine life, particularly nudibranchs with many common and rare species found in these waters. In the homes of sea fans, sponge corals, soft corals and anemone, you’ll find anemone fish, seahorses, crabs, spanish dancers, cuttlefish, octopus, barracuda, and the occasional hawksbill turtle even black tip reef shark if you’re lucky.

There are two dive sites - Hantu West and Hantu North. On the western side of the island, diving takes place between the shore and the outer reef, with a maximum depth of about 13-15 meters. Diving at Hantu North, also known as Hantu Jetty, is beneath the jetty or slightly to the west of the jetty, at a maximum depth of 8-10 meters. For data collection, we will focus on open reef areas. 

Due to its position in the middle of the Straits of Singapore, currents can be strong and unpredictable, and visibility at Pulau Hantu can range from 0.5 to 5 meters. Good buoyancy control and experience in dealing with low visibility and strong currents is a must to be effective at underwater data collection without harming the reefs and to stay safe.


Especially during the pandemic, Pulau Hantu has experienced high volumes of diving, resulting in broken corals and disturbed marine sanctuaries. ReefX has selected Pulau Hantu as our first survey site to collect long term monitoring data, which will be used to inform NParks management of the dive site and marine conservation policies, with the hopes that Pulau Hantu can remain the favourite dive site of Singapore underwater residents.

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St. John's Island (Bendera Bay)

Located on the eastern part of St John’s Island, Bendera Bay spans 3.9-hectares consisting of coral, mangrove, seagrass, sandy shore and rocky shore habitats. Bendera Bay was officially opened on 13 December 2020 by Mr. Desmond Lee, Minister for National Development and Minister-in-Charge of Social Services Integration, Speaker of Parliament Mr. Tan Chuan-Jin and Member of Parliament Ms. Nadia Ahmad Samdin together with NParks and Friends of Marine Park to pave way for education, outreach and research activities. Since then, various projects have taken place including a seagrass research project by NUS and a dive clean up by Our Singapore Reefs.


Coral habitats can support a diverse range of marine species while mangrove and seagrass habitats provide a safe nursery ground. This combination of habitats creates a unique environment potentially rich in biodiversity. Previous sightings on St John’s Island have recorded nudibranchs, flatworms, cuttlefish, reef sharks, sea fans, soft and hard corals. During 2020, there were also recorded sightings of the Indo-Pacific humpbacked dolphins in the neighbouring waters!

As a lagoon, Bendera Bay is shielded from currents and its maximum depth is 5m on high tides. Whilst shore diving is common at Bendera Bay, the ReefX expedition will reach St John's Island by dive boat charter followed by a swim-in into the lagoon.  


With the increasing amount locals and tourists heading to St John’s and Lazarus Island for a relaxing getaway, it is thus crucial that we keep a close eye on how our activities can affect the life under water. Currently under the purview of Friends of the Marine Park, the local blue community is tasked with stewardship of the site, to demonstrate that the community, and later, the public are able to conserve and enjoy such sites.

To aid this effort, ReefX has selected Bendera Bay as our next survey site to collect long term monitoring data and build an active recreational diving community around this site. Survey data collected will be used to inform NParks management of the dive site and marine conservation policies.

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Pulau Semakau

Pulau Semakau is one of the larger southern islands of Singapore, lying approximately 8km south of Singapore (Chuang, 1973) Three Malay Kampongs were established around the 1850s on the island (Hilton and Chou, 1999) where subsistence fishing and reef collection were carried out (Dikou & van Woesik, 2006) till 1978 when the inhabitants were re-settled to mainland Singapore.

Pulau Semakau, as we know today, is actually made up of two islands, Pulau Semakau and Pulau Sakeng that were joined together in 1999 to form the present larger island.  Prior to 1999, Pulau Semakau was known to have the largest remaining areas of fringing coral reefs (159.37 ha) on the west coast with an extensive intertidal mud flat and 33.43ha of mangrove system on the east coast (Chuang, 1973; Hilton & Manning, 1995). According to a general survey carried out in 1988 and 1990, the western coast of Pulau Semakau and the patch-reefs to the west were identified as one of the four areas having the highest live-coral cover.

Semakau is also the first and only remaining offshore landfill in Singapore. The Semakau Landfill which receives only incinerated ash and construction and renovation debris was commissioned in 1999 by the Ministry of National Development (MND) and covered a sea area of 350 ha forecasted to meet the country’s waste disposal needs beyond 2030. Compared to the earlier developments at other islands, there were some measures put in place to reduce the impacts of reclamation. The development obliterated the coral reef on the east of the island, but steps were taken to protect the remaining western fringing reef.

The two islands were joined by the construction of a seawall made of impermeable retainer marine clay to prevent refuse leachate from contaminating the surrounding waters. This seawall was then extended to seven km toward the south. Silt screens were positioned to prevent sediment damage throughout the construction of the perimeter bund. The island is currently under the purview of the National Environmental Agency (NEA).


Being a ReefX diver will transform your local diving experience. Our programme allows you to get hands-on with underwater data collection, deepen your understanding of marine conservation and biodiversity, whilst meeting other fellow conservation divers. We are looking for enthusiastic, nature-loving people who are not afraid of the hard work!

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