Colder water, powerful currents, exceptional visibility and some unforgettable marine-life encounters — September kept us guessing beneath the surface.
September around the Gili Islands was a month of contrasts. The water felt surprisingly cold at times, currents were stronger than usual, and some dives came with the kind of washing-machine conditions that make you appreciate a good briefing.
But the rewards were extraordinary: crystal-clear water, schools of mackerel, eagle rays, mobulas, reef sharks, and even reports of whale sharks.
From Turtle City to Shark Point and the Glenn Nusa wreck, the underwater world kept delivering surprises. Here are our highlights from September diving around Gili Meno, Gili Trawangan and the surrounding reefs.
Colder water and unusually strong currents
The beginning of September brought another drop in water temperature, with readings reaching around 26°C at times.
Currents were unusually strong throughout the period. The Glenn Nusa wreck was particularly memorable, with washing-machine-like conditions at times.
Visibility was about as good as it gets around the Gilis, creating beautiful blue-water views and excellent opportunities to observe marine life.
Turtle City really is living up to its name
If there was one place that truly deserved its name in September, it was Turtle City. Sea turtles were everywhere, with repeated encounters making it one of the month’s standout dive sites.
Bounty was another excellent spot for turtle sightings, with plenty of turtles cruising around the reef. These encounters were a reminder of why the Gili Islands are so popular with divers who want to see sea turtles in their natural habitat.
Turtle City also delivered much more than turtles. A school of mackerel put on an amazing show, while Clark’s anemonefish were seen guarding eggs beneath an anemone at around 18 metres. Clownfish eggs were also spotted at Shark Point.
These small details are part of what makes returning to familiar dive sites so rewarding. The reef is never quite the same from one dive to the next.
Eagle rays, mobulas and a big white-tip reef shark
September brought several exciting ray encounters across different dive sites.
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12 September: An eagle ray at Turtle City.
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13 September: Another eagle ray at Sunset Reef.
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19 September: An eagle ray at Meno Wall, accompanied by a large white-tip reef shark.
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20 September: A mobula ray spotted at Shark Point.
Seeing eagle rays at several sites over consecutive days was a real highlight. Their graceful movement through the water always makes an encounter special, especially when visibility is so good.
Sunset Reef and Meno Wall also seemed to offer more ray encounters than usual during this period.
At Halik, the reef sharks were looking noticeably bigger, adding to the excitement of diving the site.
Whale sharks make an appearance
One of September’s biggest surprises was a reported whale shark sighting at Turtle City. A whale shark was also reported north of Gili Trawangan.
Whale sharks are not something divers can count on seeing around the Gili Islands, which makes reports like these especially exciting.
These gentle giants are the world’s largest fish, and even a brief encounter can become a lifelong diving memory.
Frogfish, octopus and the smaller reef residents
While the bigger animals attracted plenty of attention, September was also a great month for divers who enjoy searching for the reef’s more unusual residents.
A frogfish was still hanging around the Bounty wreck, giving observant divers another chance to find this wonderfully camouflaged ambush predator. At Sunset Reef, divers spotted both a frogfish and a baby frogfish.
Octopus were being seen at dive sites across the area, adding a little extra excitement to many dives. Their ability to blend into their surroundings means that spotting one often depends on looking carefully rather than covering more ground.
These encounters are a good reminder that diving is not only about finding the biggest animal. Sometimes the most rewarding moment is discovering something small that you might otherwise have swum straight past.
The reef was busy with breeding activity
Sergeant major fish were laying eggs at both Bounty and Turtle City.
Damselfish were mating, while more algae and seagrass were noticeable around Hans Reef.
Breeding activity offers a fascinating glimpse into the daily life of a reef. Fish guarding their eggs, cleaning a nesting site or displaying courtship behaviour can be just as interesting to watch as a passing ray or shark.
It is important to observe these behaviours without interfering. Keeping a respectful distance helps prevent unnecessary stress to the animals while allowing divers to enjoy these natural moments.
What made September special?
September reminded us that the Gili Islands can offer much more than warm water and turtles. The colder conditions and unusually strong currents made site selection especially important, while the exceptional visibility opened up beautiful views across the reefs.
Ready to explore the Gili Islands underwater?
We’ll be back next month with another update from beneath the surface.
Planning a trip? See how diving conditions, marine life and visibility change from month to month in the Gili Islands. Explore all our monthly diving reports here: