Sabah and Kalimantan

The northern half of the trip focuses on the Semporna archipelago. You base yourself at a resort on Mabul or Kapalai. From there it is a 15-minute boat ride to Sipadan.

You can stay at a premium property like Sipadan-Kapalai Dive Resort or Mabul Water Bungalows. Sipadan-Kapalai Dive Resort stands on stilts over the Ligitan reefs with a house reef straight under the walkway. Mabul Water Bungalows sits on the eastern side of Mabul and features a spa alongside technical diving facilities.

Sipadan rises 600 m from the Celebes Sea floor. The resident school of chevron barracuda often forms a dense column at Barracuda Point and bumphead parrotfish move along the reef in herds most mornings. Sabah Parks issues 254 Sipadan permits a day. A guaranteed Sipadan permit comes with the right combination of resort, dive package and minimum number of nights. Exact dates depend on the resort you choose. On a properly planned trip the chance of diving Sipadan is very high. The team steers you to the combination that fits.

Outside your Sipadan days you will dive Mabul and Kapalai. These islands offer shallow sandy reefs where you can look for flamboyant cuttlefish, blue-ringed octopuses and pygmy seahorses. From Mabul and Kapalai a Sipadan day gives 3 dives.

The southern half takes you to the Maratua Atoll in the Derawan archipelago. This is a large U-shaped reef with deep drop-offs and fierce tidal currents.

The accommodation here is split between dedicated dive operations and domestic luxury resorts. You can stay at properties like Nabucco Island Resort or Nunukan Island Resort at the southern tip of the atoll. These resorts share high ecological standards and well-run diving managed by the Extra Divers network. At Nabucco Island Resort you stay on a private island with experienced dive guides. Nunukan Island Resort is connected to a four-kilometre outer house reef accessible directly from its jetty. Maratua Paradise Resort is a long-standing property featuring water villas built on stilts above the sea.

Big Fish Country | Skill level: Advanced | Ave depth: 25 m | Max depth: 30 m

This is the channel where the atoll's lagoon empties into the open sea. You drop in negatively, descend straight to the rocky substrate and deploy a reef hook to hold your position in the current. From there you can look for schooling trevally and grey reef sharks hunting in the blue.

Gorgonzola | Skill level: Intermediate | Ave depth: 20 m | Max depth: 30 m

This outer reef site features a dramatic wall dropping to a sandy plateau. You can drift past massive Gorgonian sea fans and look for resident schools of bumphead parrotfish.

Eel Garden | Skill level: Beginner to Intermediate | Ave depth: 15 m | Max depth: 20 m

Located on the sloping western shallows, this sandy reef provides a reprieve from the heavy currents. It is heavily populated by garden eels and foraging green turtles.

Manta Avenue | Skill level: All levels | Ave depth: 10 m | Max depth: 15 m

Located off Sangalaki, this site is a shallow feeding ground for reef manta rays. The mantas here feed actively at the surface rather than hovering at cleaning stations.

Kakaban Lake | Skill level: None | Ave depth: N/A | Max depth: N/A

Kakaban holds a marine lake populated by stingless golden jellyfish. It is now recovering and you can view the jellyfish from an elevated boardwalk. A strict swimming ban remains in place to protect the water quality.

There are no scheduled commercial flights linking Tawau directly to Maratua or Tarakan. The crossing relies on ferries, domestic flights and speedboats. You can follow each leg in the guide to getting from Sabah to the Derawan islands.

First you travel from your Semporna dive resort to Tawau Port. You finish diving in time to catch your resort boat and continue by road to Tawau city. The island boats do not run after dark so you overnight in a transit hotel.

Next you cross the border into Indonesia. You take a morning ferry from Tawau Port to Tarakan in North Kalimantan. The direct voyage takes 4 to 5 hours. Indonesian ferries do not operate this route on Sundays. You arrive in Tarakan in the afternoon and clear Indonesian immigration at the port. Domestic flights south depart earlier in the day so you spend a mandatory second night in a Tarakan hotel.

From Tarakan you continue to the Derawan archipelago. You take a commercial domestic flight from Tarakan to Kalimarau Airport in Berau. From the airport you take a taxi to a jetty in Tanjung Redeb or the coastal port of Tanjung Batu and board a charter speedboat. From Tanjung Redeb the river and sea journey to Maratua takes around two and a half to three and a half hours. Speedboats strictly prohibit open-water crossings after dark.

Your combination package leaves time for the crossings and a full 24 hours between your last dive and any flight.

• Days 1 to 6: Arrive in Tawau, transfer to your resort and dive the Semporna reefs. You use your Sipadan permit days here. On day six you dive only in the morning.
• Day 7: The 24-hour no-fly interval continues from your final dive on day six. You transfer to Tawau city in the late afternoon for an overnight stay.
• Day 8: Board the morning ferry from Tawau to Tarakan. Clear Indonesian immigration and overnight in a Tarakan transit hotel.
• Day 9: Fly from Tarakan to Berau, drive to the port and take a speedboat to your Maratua resort.
• Days 10 to 16: Dive the Maratua Atoll, Sangalaki and Kakaban.
• Day 17: Complete your final morning dives on the house reef.
• Day 18: Take the speedboat back to the mainland and fly to Tarakan for an overnight stay once a full 24 hours has passed since your last dive.
• Day 19: Take the ferry back to Tawau and overnight in the city.
• Days 20 to 21: Connect to your international flight home.

The team arranges the resorts, the dive boats and the major transit legs. Your accommodation and diving are secured well in advance.

The Indonesian side of the trip relies heavily on physical cash. Some resorts accept cards but you need cash for local island spending. You need Indonesian Rupiah for marine park fees, port taxes at Tanjung Batu, Kakaban entry fees and local meals. The team briefs you on exactly how much cash to withdraw on the mainland before you board the speedboat.

Malaysian telecommunications networks drop when you enter Indonesian territorial waters. Telkomsel offers the only reliable cellular coverage across the Derawan island chain so you should buy a local SIM card in Tarakan.

Be sure to arrange a dive-specific evacuation insurance policy. The team briefs every diver on emergency arrangements at booking. East Kalimantan is also a malarial zone. You must consult a doctor about prophylaxis before you travel.

Malaysia and Indonesia operate separate immigration systems. You cross an official maritime border. Both Tawau Port and Tarakan are gazetted immigration checkpoints.

The team confirms whether an Electronic Visa on Arrival suits your passport at enquiry. Any e-VoA application and its timing through the official Indonesian immigration portal are confirmed at enquiry. The All Indonesia Arrival Card requirements and timing are also confirmed at enquiry.

Your entry requirements, visa categories and customs declarations depend on your passport nationality and are confirmed at enquiry. If your trip starts and ends in Sabah the team confirms your Malaysian re-entry requirements at enquiry.

If you enjoy expedition travel and have experience in strong currents, this cross-border route gives you both Sipadan's walls and Maratua's channels. It involves early mornings, busy ferry terminals and long boat rides.

If you want to spend more of your 3 weeks diving and less time crossing borders, the Sabah Grand Dive Tour is a good fit. You can combine a week in Semporna with a week at quiet Lankayan Island Dive Resort outside its January and February closure. You get excellent diving on both of Sabah's coasts with transfers arranged between them.

Sabah and Kalimantan share a similar weather pattern. You can dive both regions all year. The best visibility runs from March to October. The months from mid-February to mid-November offer good diving with softer visibility at the ends of the season. Mid-November to mid-February brings a mix of cloud, rain and sun.

Sabah Parks closes Sipadan to all visitors for the entire month of November every year. The other islands in the Semporna archipelago stay open, as do the resorts on Maratua.

• Getting from Sabah to the Derawan islands
• Sabah Grand Dive Tour
• Sipadan Classic
• Maratua

Send your dates, the names of everyone travelling and your certification levels. The team comes back with an itinerary that works for the tides and ferry schedules.