Coral Triangle · Indonesia
Krakatau & Sangiang Island
Day-boat dives on the flanks of Krakatau's volcanic islands
The Sunda Strait between Java and Sumatra is dived as day trips by speed boat from Anyer and Carita on the Banten coast. Two island groups share the boats: Sangiang, a nature reserve with soft-coral reefs at Legon Waru and Tanjung Bajo, and the Krakatau islands, where Legon Cabe lies off Rakata and Batu Mandi beside Anak Krakatau. Most dives run from 6 to 24 m (20 to 80 ft) on volcanic rock and reef.
About diving in Krakatau & Sangiang Island
Diving here runs from day boats. Divers meet at a dive centre on the Anyer or Carita coast in the morning and cross by speed boat, either to Sangiang, about 45 minutes across, or further out to the Krakatau islands for two dives. There are no regular boats to Sangiang, so the island is reached by dive boat or by charter. Open water on the way out can throw up high waves and hard current.
The two groups look different underwater. Around Krakatau the bottom is dark volcanic rock, with deep walls and pinnacles left by past eruptions; emperor angelfish stand out against it and schools of Moorish idols cross the reef. Sangiang is softer ground: its reefs are mainly soft coral, with barracuda, batfish, pipefish, boxfish, clownfish and nudibranchs, and some sites carry light to moderate current.
This suits Jakarta divers with only a weekend free, and Open Water divers comfortable in some current. Krakatau sits inside the reserve of Ujung Kulon National Park. Anak Krakatau erupted again from 4 September 2026, and its eruptions have disrupted fishing, schools and flights in the area around it. Sangiang, a nature reserve with soft-coral reefs, is the other day trip.
Best time to dive Krakatau & Sangiang Island
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Fair | Fair | Good | Good | Good | Good | Good | Good | Good | Good | Good | Fair |
No single month stands out; the very windy west monsoon from December to February is the time to avoid, and wind sets the visibility.
Best months: March, April, May, June, July, August, September, October, November
Dive types & marine life
Sea turtles are easy to find around Sangiang. At Krakatau, whitetip reef sharks are only an occasional sighting. No animal here is tied to a particular month.
- Coral garden
- Reef
- Drift
- Sea turtles
- Nudibranchs
- Reef sharks
- Barracuda
- Reef fish swarms
Best dive sites in Krakatau & Sangiang Island
- 1
Legon Cabe
Shallower Krakatau dive beside Rakata island, from 6 to 18 m (20 to 60 ft).
- 2
Batu Mandi
Deeper dive next to Anak Krakatau, from 18 to 24 m (60 to 80 ft).
- 3
Rakata
Drift dive on a gentle current off the southeast end of Rakata island.
- 4
Karang Serang
Rocks whitened by seabirds that mark a dive off Anak Krakatau.
- 5
Tanjung Bajo
Sangiang site where yellowtail fish parade deeper than 20 m.
- 6
Legon Waru
Sangiang reef built mainly of soft corals, like the island's other sites.
Site guides
Reef
Deeper second dive beside the active cone of Anak Krakatau
Reef
Bird-whitened rocks off Anak Krakatau mark the dive
Reef
Opening dive of the Krakatau day, beside Rakata island
Gentle eastward drift with plenty of green turtles
How to get to Krakatau & Sangiang Island
Soekarno–Hatta International Airport serves Jakarta. Anyer is about 3 hours' drive from the city in usual traffic, and Carita is about 3 hours by car. The dive centres sit on this coast, and boats to Sangiang leave from Paku port at Anyer or the Mabak jetty near Merak.
Questions divers ask
What certification is needed to dive Krakatau and Sangiang?+
Open Water certification is required. Legon Cabe stays between 6 and 18 m (20 and 60 ft), while Batu Mandi reaches 24 m (80 ft) and the Rakata drift runs on a gentle current.
How do divers get to Krakatau and Sangiang?+
Fly into Soekarno–Hatta International Airport in Jakarta and drive about 3 hours to Anyer or Carita, where the dive centres are. Speed boats run from there; Sangiang is about 45 minutes from Paku port at Anyer or the Mabak jetty near Merak.
When is the best time to dive the Sunda Strait?+
No single month stands out as best. The very windy west monsoon from December to February is the time to avoid, since visibility depends on the wind. Water stays between 27 and 30 °C (81 and 85 °F) through the year.
Is Anak Krakatau still active?+
Yes. It erupted again from 4 September 2026, and its eruptions have disrupted fishing, schools and flights nearby. Batu Mandi and Karang Serang lie right beside it; Sangiang, a nature reserve with its own soft-coral reefs, is the other day trip.
Sources
- Tour Banten: one day dive trip — Tour Banten
- Krakatau Dive Tour — PT. Panorama Krakatau Tour
- Krakatau Dive Tour (Java) — Krakatau Tour
- Mambruk diving package (Wayback) — Mambruk Hotel & Convention
- Pulau Sanghyang — Zentacle
- Takjub! Ini Dia Spot Diving Terbaik di Banten — detikTravel
- Krakatoa — Wikipedia
- Sangiang — Wikipedia
- Anyer — Wikivoyage
- Ujung Kulon National Park — Wikivoyage
- Labuan water temperature — seatemperature.org
- Soekarno–Hatta International Airport — Wikipedia
Embed
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