Ambon, Home to a Strange Little Underwater World

October 2025. I’m back in Indonesia. First stop: the island of Ambon in the Moluccas archipelago. My companions: about ten passionate underwater photographers, brought together by marine biologist Steven Weinberg. Our subjects: odd little creatures hiding in the grey sand on the ocean floor.

A Muck Diving Destination

Like Lembeh Strait in North Sulawesi, Ambon Bay is a renowned muck diving destination. It’s a specific style of diving that involves swimming slowly just above the seabed to scrutinize every square centimeter.

The goal? To uncover a strange array of small mollusks, fish and crustaceans — sometimes tiny and often masters of camouflage. Curiosities of nature that are endlessly fascinating for divers passionate about marine biology and macro photography.

Read more ➜ Dive into another world in the Philippines: Anilao and Romblon

We are staying at Ambon Dive Resort, run by the lovely Mathieu and Sri, a French-Indonesian couple. It’s a charming, diver-oriented lodge, with a handful of hillside bungalows tucked away in the greenery. We’re away from the city of Ambon, near a small fishing village, close to the mouth of the bay. Every day, we head out to explore the dive sites, usually doing two dives, and sometimes three or even four, for the most dedicated among us.

Guides with lynx eyes

At first glance, the underwater landscape of Ambon Bay isn’t all that appealing: the bottom is a mix of grey sand, stones, seaweed and coral debris, with patches of rubbish here and there. Only a few scattered coral “clumps”. Often mediocre visibility.

At the beginning, you wonder what you’re doing there. But it doesn’t take long to understand. The sites are teeming with life: nudibranchs, flamboyant cuttlefish, ghost pipefish, scorpionfish, frogfish, bizarre crabs, and unusual shrimp… Little critters measuring from a few millimeters to a few centimeters, often impossible to spot if you don’t know where to look.

Lucky for us, we can count on the lynx-like eyes of our Indonesian guides Iwan, Benito and Anga. Without them, we would have missed almost all these wonders! The success of a muck dive largely depends on the guide, their spotting talent, their knowledge of the site and the fauna, and their ability to communicate underwater to draw our attention to discoveries.

After that, to bring back images, you need lots of patience and passion. You must know how to swim near the bottom without kicking up clouds of sand with your fins; approach your subject without scaring it; frame and focus with millimeter precision despite the current; angle your strobes well; and press the shutter at precisely the right moment…

Plastic pollution

Day after day, we’re delighted by the richness of the bay, despite the sad sight of plastic pollution. A plague in Indonesia, particularly visible in Ambon.

It’s no surprise, I knew what to expect. The city of Ambon, capital of the Moluccas, has grown along the coastline around the bay, with a high population density (the urban area was estimated at over 600,000 inhabitants in 2025). Waste collection and processing are notoriously insufficient.

As a result, tons of trash are discarded into the environment, wash into rivers, and accumulate along the coastline. To this is added the debris carried by ocean currents, which washes ashore with each tide.

The problem is well known, and the solutions are complex to implement. Recent initiatives include the French scientific vessel Plastic Odyssey, which made a stopover in Ambon in June 2024, to raise public awareness. The local government, for its part, announced in November 2025 the deployment of a small fleet of boats dedicated to the daily cleaning of the bay, as well as a strengthened cooperation with the Swiss association The SeaCleaners. These measures at sea are intended to complement a vast waste management program on land. These efforts are a step in the right direction, but significant resources and time will likely be needed before the situation improves…

In short, for “normal” tourists and divers who do not practice muck diving, this side of Ambon might not seem very appealing. Yet this bay, still very rich in biodiversity, continues to attract marine biologists and naturalist photographers, for whom it remains a fabulous playground.

A psychedelic dream

Upon arrival, we had a somewhat naïve dream, a hope: “Do you think we will see the psychedelic frogfish?” An animal as strange as it is rare, spotted here in Ambon Bay in 2008 and, to date, never observed alive elsewhere.

Recognized in 2009 as a new species, this fish belongs to the Antennariidae family and has the scientific name of Histiophryne psychedelica. Since then, very few divers have had the chance to admire its funny flattened face and psychedelic welts.

Our repeated questions about the psychedelic frogfish make our Indonesian guides laugh. They don't want to discourage us, but it's been a long time, “several years”, since anyone has seen one in Ambon Bay. But “you never know”...

No need to drag out the suspense: none of us will see it! But there's plenty of other “psychedelic” critters to photograph.

In the evenings, we extend the pleasure by screening a selection of our images under the expert yet friendly eye of Steven Weinberg, a marine biologist well known in the French-speaking diving community for his species identification guides, true reference works. What could be more convenient, when trying to put a name to a little critter, than having “the” Weinberg in person right there with us?

Coral reefs

For “classic” tropical diving in Ambon – coral reefs and schools of fish – you need to venture outside the bay. But these trips are the exception rather than the rule, because of longer navigation time and the need for favorable swell and weather conditions.

So I switch to my wide-angle setup for these dives – fisheye lens and dome port. These are beautiful ambient dives, offering a welcome change of scenery between two muck dives. One of the most beautiful is through a cave lined with large sponges and colourful gorgonians, with wide underwater arches opening onto blue. Splendid!

It’s also an opportunity to discover white-sand, postcard-perfect beaches during surface intervals, for tea and biscuits. A small glimpse below…

After Ambon, I returned to a small island where I had been several times in the past, before the Covid pandemic: Bangka, in North Sulawesi. I'll share that story in an upcoming post... 😎