The short answer: if you can only travel in one month, here is where I would dive, from my own logbook of 1,500-plus dives and more than 40 liveaboard trips. December to April: Raja Ampat and the Maldives for mantas and sharks in the clearest water of the year. March to June: Tubbataha’s short season, the Galapagos for hammerheads, Belize before the hurricanes. May, June, September and October: Komodo, before and after the July–August crowds. Bali: May for the Nusa Penida mantas, July to October for mola mola, and November for macro and nudibranchs at Tulamben. Late September to November: the Banda Sea for hammerhead schools, with October the peak; October is also peak season in Raja Ampat, and Triton Bay reopens at the end of the month. Any month: Cocos Island. The calendar below gives one first pick and one back-up for every month of the year, and every entry is somewhere I have dived myself, in that month or close to it.
How I Built This Dive Calendar
Last updated October 2026, after my latest Banda Sea crossing on the Scubaspa Zen.
Dive seasons are usually copied from operator websites. This calendar is built the other way round: from the months I actually dived each place, what turned up, and what went wrong. I have dived the Maldives in a storm in August and in glass-flat water in December, Komodo in every season since 2006, the Banda Sea on six trips to Suanggi, and the Galapagos in March with a 7 mm suit. Where I have not dived a destination in its best month, I say so, and I lean on my own trips in the shoulder months instead.
Three rules shaped the picks:
- Animals over weather. The best month is the one the hammerheads or mantas turn up in, not the one with the bluest sky. In Komodo and the Maldives, the plankton months mean worse visibility and far more mantas.
- Crowds count. In July 2026 I counted about 50 boats in Komodo National Park. The same sites in May or October are a different experience.
- Closed means closed. Tubbataha opens for three months; Triton Bay is effectively shut from May to September. A calendar that ignores that sends you to an empty harbour.
Every destination here links to my full first-hand review or guide, and my ranking of the best dive destinations in the world covers the same places by quality rather than by month.
How to Read the Calendar: Peak, Good, Possible and Closed
My infographic of where to dive each month sorts every month into one of four bands, and they mean something specific:
- Peak. The animals and the conditions line up: the Banda hammerheads in October, Raja Ampat’s clearest water in January and February, the Maldives channels in December. Boats fill a year out, so book early.
- Good. The shoulder months. Conditions are still right, there are fewer boats, and cabins are easier to find. Komodo in May, June, September and October is the clearest example.
- Possible. Diveable, but you trade something: visibility for mantas, a rough crossing for plankton, cold water or crowds. Komodo in July, or the Maldives in August.
- Closed. No boats sail, or the park is shut. Tubbataha outside mid-March to mid-June, Triton Bay from May to September, and Socorro from June to October.
Where to Dive Each Month at a Glance
| Month | My first pick | Back-up | What’s peaking |
|---|---|---|---|
| January | Raja Ampat | Maldives | Mantas at Misool, clearest Papua water, Maldives channel sharks |
| February | Raja Ampat | Galapagos, Socorro | Best Raja Ampat visibility; Galapagos hammerheads in warmer water; humpbacks and giant mantas at Socorro |
| March | Galapagos | Tubbataha (opens mid-month) | Hammerhead schools at Wolf and Darwin; Red Sea season starts |
| April | Cocos Island | Tubbataha, Belize | Hammerheads from the check dive; Philippines’ healthiest reef |
| May | Komodo | Bali (Manta Point) | Komodo before the crowds; peak manta month at Nusa Penida |
| June | Tubbataha (last weeks) | Red Sea Deep South, Komodo | Warm Red Sea water, Daedalus hammerheads, Belize before hurricanes |
| July | Bali (Nusa Penida) | Halmahera | Mola mola season opens; Komodo busiest |
| August | Bali (mola) | Sea of Cortez, Halmahera | Mola peak, whale sharks in Baja; Maldives storms |
| September | Komodo | Maldives (Hanifaru), Bali | Komodo quiet again; Hanifaru manta trains; Red Sea season reopens |
| October | Banda Sea | Raja Ampat, Komodo, Red Sea | Hammerhead peak at Suanggi; Raja Ampat in peak season; Triton Bay reopens late month |
| November | Banda Sea / Bali (Tulamben) | Raja Ampat, Triton Bay, Sea of Cortez | Hammerheads, Tulamben macro and nudibranchs, Raja Ampat mantas return |
| December | Maldives | Raja Ampat | Calm channels and the sharkiest dives of my year; Komodo mantas begin |
Year-round: Cocos Island in Costa Rica, which I dived in April, has no bad month for hammerheads. Bali’s Tulamben and Amed coast dives well in any month if you go in the morning.
Jump to a month: Jan · Feb · Mar · Apr · May · Jun · Jul · Aug · Sep · Oct · Nov · Dec · Water temperature and wetsuits
Where to Dive in January
January is Raja Ampat’s month. The north-west monsoon has settled, the water is at its clearest and the southern islands around Misool are at their most accessible. I stayed at Misool Resort in January 2021 and saw mantas on more than half of my dives, plus a sardine bait ball with mobula rays at Puri Pinnacle. At Magic Mountain, more than 15 reef and oceanic mantas stayed with us for a full 60-minute dive. My ranking of the best Raja Ampat liveaboards covers the boats that are in the archipelago in January.
Back-up: the Maldives. January sits in the north-east monsoon, which means calm crossings, the clearest water and sharks lined up on the incoming tide in the channels. I have not dived the Maldives in January itself, but my December trip on the same side of the monsoon gave me more than 100 sharks in one channel, and the conditions carry through to April. My guide to diving in the Maldives has the month-by-month detail.
Not January: the Seychelles. My only four dives there were in rough January seas, which is why they are not on my list yet.
To find the best deals on liveaboards operating in Indonesia this January, click here, or check the next departures of the Emperor Harmoni.
Where to Dive in February
February is the other half of Raja Ampat’s best window. Visibility stays at its peak, the manta cleaning stations are busy, and the boats that migrated down from Komodo in October are all here. On the Dewi Nusantara and the Emperor Harmoni I have had more fish on one dive at My Reef than anywhere else in the world, with sharks we gave up counting and an oceanic manta passing through. Read is Raja Ampat the best diving in the world? for why it tops my list.
Back-up: the Galapagos. The warm season from December to May brings calmer seas and the densest hammerhead schools at Wolf and Darwin. February is also one of the cheaper months to find a berth before the March–April peak.
Also good: Triton Bay. My first trip there, on the Ilike from 27 January to 9 February 2019, ran from Sorong down to Kaimana, and it was in that window that five whale sharks of more than 5 metres fed together under the Bitsjara Bay bagans. And Komodo’s south, where December to February is manta season at Manta Alley, with lower visibility as the price: around 30 mantas fed there on my best southern dive. And Socorro in Mexico, where January to March is humpback season, with giant mantas on the same dives.
To find the best deals on liveaboards operating in Indonesia this February, click here.
Where to Dive in March
March is when I dived the Galapagos, and it gave me the best big-animal diving of my life. Seven nights on the Galapagos Sky in March 2024, after a week on the Theory, delivered schooling hammerheads at Darwin’s Arch and Wolf, four oceanic mantas at Cape Marshall, a school of more than a thousand barracuda and a mola mola. The price was cold: the thermocline fell from 24°C to 14°C within two metres, and I wore every millimetre of a 7 mm suit. My Galapagos diving guide covers the seasons, the boats and the costs.
Back-up: Tubbataha. The park opens around the middle of March, and the first boats of the season find the reef untouched since June. If you want a berth, you are already late; see April.
Also good: the Red Sea, where March opens the spring window, and the shorter Banda Sea hammerhead season around March to May, which is quieter than October and less reliable. Palau is also in the middle of its October–May dry season, the best window for Blue Corner and German Channel.
To find the best deals on liveaboards operating in the Galapagos this March, click here, or check the next departures of the Galapagos Sky.
Where to Dive in April
April is the month I dived Cocos Island, and it remains the best check dive of my life: a school of six hammerheads within five minutes at Manuelita, and more than 70 hammerheads over that first day’s three dives around the island. Over ten days on the Okeanos Aggressor II we had more than 30 hammerheads surrounding us at Dirty Rock, a huge tiger shark at Alcyone and dolphins playing with us for ten minutes at Punta Maria. Cocos has no real off-season for sharks; April simply happens to be when I went, and I would go again in any month.
Back-up: Tubbataha and Belize. April is the heart of Tubbataha’s mid-March to mid-June season, with mild current that suits newer divers. Belize’s March to June window is the calm, dry stretch before hurricane season, and the week I spent on the Belize Aggressor III around Turneffe and Lighthouse Reef, straight after Cocos in April 2022, is the gentlest liveaboard I can recommend.
Also good: Halmahera. My first trip there, on the Jakare in April–May 2021, found one site with at least 100 blacktips and a school of sweetlips swimming with about ten hunting whitetips at Tobias Point. Maumere in Flores also opens its dry season in April, and April–May is the local window for whale sharks; my Maumere diving guide has the sites.
To find the best deals on liveaboards operating in Costa Rica this April, click here, or check the next departures of the Okeanos Aggressor II.
Where to Dive in May
May is my favourite Komodo month. The dry season has arrived, the northern sites are at their best, and the park is still weeks away from the July crush. I have dived Komodo since 2006 on the Tiare, the Moana and others, and Castle Rock, where I once hooked in to a current strong enough to tear a mask off and watched more than 30 sharks hunting, is the dive I would send anyone to first. My Komodo diving guide and best Komodo liveaboards have the boats and the sites.
Back-up: Bali’s Manta Point. May is my manta month at Nusa Penida. On my best May dive, more than six mantas circled the cleaning station at once. The whole Penida coast is diveable from April, and the water has not yet dropped to the chilly mola-season temperatures.
Also good: Maumere in Flores, which I sailed from on the Mermaid I in late May 2023 on the way to Komodo, with dolphins beside the boat every day and the muck sites in front of the resorts at their calmest; the last of Belize’s dry season; the Galapagos warm season (which ends in May); Halmahera; and the shorter Banda hammerhead window.
To find the best deals on liveaboards operating in Indonesia this May, click here, or check the next departures of the Tiare.
Where to Dive in June
June gave me two very different trips. Six nights on the Infiniti in June 2023 were the last weeks of Tubbataha’s season: a tornado of more than 400 barracuda at Shark Airport, a shark nursery with more than 40 small sharks on the Southwest Wall, and around 20 Napoleon wrasse at South Park. I had expected more big fish; what I got was the healthiest reef on my list. Book this more than 12 months ahead.
Back-up: the Red Sea Deep South. June 2021 on the Red Sea Aggressor III was 27–28°C water, three hammerheads at Daedalus with one circling us for more than five minutes, two hunting at Elphinstone and a snorkel with more than 50 dolphins at Fury Shoal. The textbook Red Sea months are March to May and September to November, but June in the south was warm, calm and empty. My Red Sea diving guide splits the north, Sharm and the Deep South by season.
Also good: Komodo, still in its sweet spot before the crowds, and Belize before the hurricane season.
To find the best deals on liveaboards operating in the Philippines this June, click here, or check the next departures of the Infiniti.
Where to Dive in July
July is when the mola mola start coming up from the deep at Nusa Penida, and Bali is home water for me. At Crystal Bay the sunfish rise to be cleaned by bannerfish between July and October, with August and September the peak. The water at depth drops to 18–22°C, so pack a 5 mm suit and a hood; the 4-knot currents at Penida are real. The rest of the island is at its calmest: July to September is peak clarity at Menjangan, and the Liberty wreck at Tulamben is the best easy diving in Bali. My guide to diving in Bali covers every coast.
Back-up: Halmahera. Few boats run here, which is the point. The Patinti Strait has given me more sharks and mantas than people on both of my trips.
Not July: Komodo, unless you have no choice. In July 2026 I counted about 50 boats in the park. The diving is as good as ever; the sites are not yours.
To find the best deals on liveaboards operating in Indonesia this July, click here.
Where to Dive in August
August is peak mola in Bali, and the month I would choose for Nusa Penida if the sunfish are the goal. It is also the month of my second Halmahera trip, on the Ambai in August 2023, where the sheer volume of fish at Siko Pinnacle was staggering.
Back-up: the Sea of Cortez. August to November brings the warmest water and the whale sharks to Baja. My Sea of Cortez liveaboard, a week on the Quino el Guardian through the Midriff Islands at the end of July and start of August 2019, gave me whale sharks of 3 to 7 metres in Bahía de los Ángeles, more than 50 sea lions at San Pedro Mártir and a hammerhead at El Moro, in some of the easiest diving I have done.
Not August: the Maldives, unless Hanifaru is the goal. My August weeks there were the roughest of my diving life. In August 2024 White Pearl spent five of seven nights sheltering near Malé in one of the worst storms of the year, and I managed 13 dives; the same month, bad weather stopped the Duke of York from crossing to Ari at all. The reward for the south-west monsoon is plankton, and plankton means mantas, so August to September is Hanifaru Bay season in Baa Atoll. Go on a big, stable boat or not at all.
To find the best deals on liveaboards operating in Mexico this August, click here.
Where to Dive in September
September is Komodo’s second sweet spot. The July–August boats have gone, the dry-season visibility holds, and Castle Rock, Batu Bolong and Crystal Rock are back to a manageable number of groups. If you want mantas, sharks, healthy reef and 70 minutes of nudibranchs at Sangeang on the same trip, this is the month. I compare it head to head with the Maldives in Maldives vs Komodo.
Back-up: Hanifaru Bay. In September I watched manta trains of 20 or more feeding at Hanifaru in Baa Atoll, the single best manta spectacle I have seen in the Maldives. It is snorkel-only in the core zone, the water is green, and the crossings are still monsoon-rough, so it is a trip for one reason.
Also good: Bali, still in mola season with the water clearing; the Red Sea, where the autumn window opens; and the Sea of Cortez, where September to November is the best visibility at Cabo Pulmo.
To find the best deals on liveaboards operating in Indonesia this September, click here.
Where to Dive in October
October is the one month I would not trade. The Banda Sea hammerheads are a bet rather than a promise, but late October is when the bet pays: on the Sea Safari 6 I saw more than 200 hammerheads in five separate schools, including a school of 30 at Suanggi, with sea snakes at Manuk. I have now dived Suanggi on six trips, and in October 2026, crossing the Banda Sea from Ambon on the Scubaspa Zen, we counted 11 hammerheads at the Jackpot site. Every Banda trip starts or ends in Ambon, which is worth two days of muck diving on its own.
Back-up: Raja Ampat, Komodo and the Red Sea. October is peak season in Raja Ampat, with the liveaboards back from Komodo for the October–April season. Most operators will tell you October is too early for Misool, straight after the monsoon. If the waves allow it, it is actually the best time of the year there: the sites are still full of mantas and clouds of silversides, because the divers and the fishermen have not arrived yet. It is the most fish you will see anywhere. October is the last of Komodo’s quiet dry-season months before the boats sail east for Banda and Raja Ampat. In the Red Sea, October sits squarely in the autumn window for Daedalus, Elphinstone and the Brothers.
Also good: Bali for the last of the mola and the start of nudibranch season at Tulamben and Amed (October–November), and the first boats into Triton Bay at the end of the month. Maumere’s dry season closes in October.
To find the best deals on liveaboards operating in Indonesia this October, click here, or check the next departures of the Sea Safari 6.
Where to Dive in November
November splits between the Banda Sea, still in its hammerhead window, and Tulamben on Bali’s north-east coast, where November is the best month of the year for macro and nudibranchs. My November 2022 crossing on the Scubaspa Zen and my October trip on the Neomi gave me hammerheads every single day, a manta on a safety stop and sperm whales breaching beside the boat.
Back-up: Raja Ampat. The season is in full swing and the mantas return to the cleaning stations from November, with the water still clearing towards its January peak. The Sea of Cortez is also in its warm, whale-shark window, and Maumere’s November–December period is when whales are seen offshore.
Also good: Triton Bay, which reopens after five months shut. Triton Bay is the rarest luxury in modern diving, a world-class destination with nobody else in it: on two trips, on the Ilike in February 2019 and the Seahorse, we never saw another dive boat in three days, and the whale sharks were waiting under the Bitsjara Bay fishing platforms. Expect green water and 10–15 metres of visibility; that is the trade. My complete guide to diving Triton Bay has the logistics from Kaimana. In Bali, the corals spawn about a week after the November or December full moon.
To find the best deals on liveaboards operating in Indonesia this November, click here, or check the next departures of the Seahorse.
Where to Dive in December
December 2025 on the EcoPro Seascape was the opposite of my August storms: open visibility in the channels and the most sharks I have seen in the country. At Miyaru Kandu, more than 100 sharks and around 20 eagle rays on the incoming tide, the sharkiest dive I have done in the Maldives. The north-east monsoon has settled, the liveaboards cross between atolls without drama, and the mantas sit on the west side of the atolls until April. For a first Maldives trip, December to March is the window; my ranking of the best Maldives liveaboards covers the boats.
Back-up: Raja Ampat. December is full season, with the mantas back and most of Indonesia’s best boats in the archipelago. If you want the whole Indonesian fleet in one place, see my best luxury liveaboards in Indonesia.
Also good: Komodo’s south for the start of manta season, with the Moana one of the few boats that stays in the park year-round, and the Galapagos as the warm season begins.
To find the best deals on liveaboards operating in the Maldives this December, click here, or check the next departures of the EcoPro Seascape.
Best Time to Dive, Destination by Destination
The same calendar of where to dive each month, turned around: if you already know where you want to go, these are the months I would pick, the months I would avoid, and the months I have dived there myself.
| Destination | Best months | Avoid or closed | Months I dived it |
|---|---|---|---|
| Raja Ampat | October–April; peak in October ( most fishes) and January–February (clearest) | No real avoid month: May–September the south is rough and most boats leave, but the central and northern areas still dive well | January and the Oct–Apr season, 10+ trips |
| Galapagos | December–May for hammerheads and warmer water | No bad month; June–November colder, rougher | March |
| Komodo | May, June, September, October; mantas Dec–Feb | July–August crowds | Every season since 2006 |
| Cocos Island | Year-round | None | April |
| Banda Sea | Late September–November, October peak; shorter March–May window | June–August | October, November (six Suanggi trips) |
| Maldives | December–April calm and clear; Aug–Nov for Hanifaru mantas | August crossings in a bad year | August, September, December |
| Triton Bay | October–April | May–September (effectively closed) | Late January–February 2019 (Ilike), October 2026 |
| Tubbataha | Mid-March–mid-June only | Closed the rest of the year | June |
| Red Sea | March–May, September–November | Deep winter in the north for cold | June (Deep South), earlier northern trips |
| Halmahera | Few boats; April–May and August worked for me | Unknown; too few trips run to say | April–May, August |
| Bali | April–November; Nusa Penida mantas May; mola July–October; Tulamben macro and nudibranchs November | December–March run-off on the north coast and Padang Bai | Every month, ten years |
| Sea of Cortez | August–November | Winter for cold water | Late July–early August 2019 |
| Belize | March–June | Late summer and autumn hurricane season | April 2022 |
| Maumere (Flores) | April–October; whale sharks Apr–May; whales Nov–Dec | Wet season | Late May 2023 (Mermaid I), plus an earlier trip |
| Ambon | October–November, as the Banda gateway | None for muck | October, November |
| Socorro | November–May; humpbacks January–March | June–October (no liveaboards sail) | A handful of dives |
| Palau | October–May (dry season) | June–September (wetter and windier, still diveable) | Once |
Best Time to Dive the Galapagos
December to May, when the water warms, the seas calm and the hammerhead schools at Wolf and Darwin are at their densest. I dived in March and wore a 7 mm suit for the 14°C thermoclines, so warm is relative. There is no bad month: the cooler June to November season brings whale sharks to Darwin and bigger seas. Full detail in my Galapagos diving guide.
Best Time to Dive Belize
March to June, the dry, calm stretch before hurricane season, when the Great Blue Hole’s stalactites at 30–40 metres and the reefs of Turneffe and Lighthouse sit in flat water. It is the easiest liveaboard week on my list, with up to five dives a day and minimal current.
Best Time to Dive Raja Ampat
October to April, with October, January and February the peak months; January and February are the clearest and the best months to reach Misool. Mantas peak from November to April. From May to September the south-east monsoon turns the water over and most liveaboards relocate to Komodo, which is why the two destinations pair so well across a year. There is no month I would truly avoid, though: even from May to September you can still dive the central and northern areas. And in October, if the waves allow it, Misool has the most fish of the year, before the divers and fishermen arrive.
Best Time to Dive the Maldives
December to April for a first trip: calm seas, the clearest water, and channel sharks in three figures on the incoming tide. May to November is the south-west monsoon, with rougher crossings and plankton, which is exactly why Hanifaru Bay’s mantas feed from August to October and the whale sharks of South Ari are easier to find. Mantas switch sides with the monsoon: west side of the atolls from December to April, east side from May to November.
Best Time to Dive Komodo
May, June, September and October: dry-season visibility without the July–August crowds. December to February is manta season in the south at Manta Alley, with greener water. The park is diveable all year, and my Komodo diving guide explains how the moon phase matters as much as the month: full and new moons bring the strongest currents at Castle Rock and Shotgun.
Best Time to Dive Cocos Island
Any month. I went in April and counted more than 70 hammerheads on the first day of diving, starting with a school of six on the check dive. The rainy season from June to November is often quoted as the big-animal peak, with more hammerheads and the occasional whale shark, but Cocos is a 36-hour crossing from Puntarenas in any month, and the sharks did not seem to know what season it was.
Best Time to Dive the Red Sea
March to May and September to November, when the northern wrecks are warm enough and the Deep South reefs of Daedalus and Elphinstone are in season for hammerheads. My June trip in the Deep South was 27–28°C and empty of other boats; the north runs 2°C cooler. Winter diving in the north means a 7 mm suit.
Best Time to Dive in the Philippines
For Tubbataha, a UNESCO World Heritage site and the only Philippine destination I have dived, the answer is forced on you: the park opens from about mid-March to mid-June and the boats sell out more than a year ahead. I went in June on the Infiniti. Malapascua, Anilao and Dauin are on other calendars; I have not dived them yet.
Best Time to Dive Fiji and Palau
Fiji: I have dived from a Yasawa Islands resort and done the Beqa Lagoon shark dive, with bull sharks at arm’s length, which is a handful of dives rather than a season’s worth, so I will not rank its months; the soft-coral window most divers quote is April to October. Palau: I dived it once, with giant mantas, a tiger shark and reef sharks. The dry season, October to May, is the main diving season, with the calmest conditions for Blue Corner and the mantas at German Channel; June to September brings more wind and rain, but the boats and dive centres keep diving year-round.
To find the best deals on liveaboards operating in Palau, click here.
Best Time to Dive Socorro
Socorro, in Mexico’s Revillagigedo Islands, is liveaboard-only, with a fixed season from November to May; the boats do not sail there in the summer months. January to March is humpback whale season, when the whales share the water with the giant mantas that are the reason most divers make the long crossing from Baja California. November and May, at either end of the season, are the quieter months.
To find the best deals on liveaboards operating in Socorro, click here.
Where to Dive for Mantas, Hammerheads and Whale Sharks, by Month
| Animal | Peak months | Where I saw them | My best count |
|---|---|---|---|
| Hammerhead schools | Oct–Nov (Banda); Dec–May (Galapagos); any month (Cocos) | Suanggi, Wolf and Darwin, Manuelita | 200-plus in a week, Banda Sea; 70-plus in one day, Cocos |
| Reef mantas | Nov–Apr (Raja Ampat); Dec–Feb (Komodo south); May (Bali); Aug–Oct (Hanifaru) | Magic Mountain, Manta Alley, Manta Point, Hanifaru Bay | Around 30 at Manta Alley; trains of 20-plus at Hanifaru |
| Oceanic mantas | Dec–May (Galapagos); Nov–Apr (Raja Ampat) | Cape Marshall, Magic Mountain | Four at Cape Marshall; 15-plus mixed at Magic Mountain |
| Whale sharks | Oct–Apr (Triton Bay); Aug–Nov (Sea of Cortez); year-round (South Ari) | Bitsjara Bay bagans, Bahía de los Ángeles | Five together, each over 5 m, Triton Bay |
| Reef sharks in numbers | Dec–Apr (Maldives channels); May–Jun and Sep–Oct (Komodo); Oct–Apr (Raja Ampat) | Miyaru Kandu, Castle Rock, My Reef | 100-plus in one channel, Maldives |
| Mola mola | Jul–Oct (Bali), Aug–Sep peak | Crystal Bay, Nusa Penida | Reliable in season; one in the Galapagos in March |
For whale sharks I rank every place I have swum with them in the best places to dive with whale sharks. For the best months and sites for each animal, see my guides to the best places to dive with manta rays and to diving with hammerhead sharks.
Water Temperature and Wetsuit Guide by Month
Knowing where to dive each month is half the plan; the other half is what to wear. The month changes the water as much as the destination does. These are the temperatures on my own dives, and the suit I would pack for each.
| Destination | Month or season | Water temperature | Suit to pack |
|---|---|---|---|
| Maldives | December | 27–30°C | 3 mm |
| Cocos Island | April | 28–29°C, with 21°C thermoclines | 3 mm, or 5 mm for the thermoclines |
| Banda Sea | October–November | 27–29°C | 3 mm |
| Triton Bay | October–February | 26–29°C | 3 mm |
| Komodo (north) | Dry season, May–October | 26–29°C | 3 mm |
| Komodo (south) | Manta season, December–February | Around 24°C | 5 mm |
| Red Sea Deep South | June | 27–28°C (the north runs 2°C cooler) | 3 mm, or 7 mm in the northern winter |
| Sea of Cortez | Late July–August | 22–30°C | 3–5 mm |
| Nusa Penida, Bali | Mola season, July–October | 18–22°C at depth | 5 mm and a hood |
| Galapagos | March | 24°C, falling to 14°C at the thermocline | 7 mm |
The two months that catch people out are March in the Galapagos, where the thermocline can drop ten degrees within two metres, and August at Nusa Penida, where the mola come up with the cold water. Both are worth the extra neoprene.
Planning a Dive Trip Around the Calendar
- Follow the boats. Indonesia’s liveaboard fleet moves with the seasons: Komodo from May to October, Banda in October–November, Raja Ampat and Triton Bay from November to April. Book the boat, not the region, and let it carry you to the right place. My best luxury liveaboards in Indonesia lists which boats run which circuit.
- Book a year out for the fixed seasons. Tubbataha sells out more than 12 months ahead; the best Galapagos and Banda boats nearly as fast.
- Pack for the month, not the destination. The Maldives in December is 30°C and a 3 mm; the Galapagos in March is 14°C at the thermocline and a 7 mm; Penida in August needs a 5 mm and a hood. My scuba gear list and liveaboard packing list cover the rest, and the water temperature table above has the suit for each trip.
- Watch the moon as well as the month. In Komodo and the Maldives channels, full and new moons bring the strongest currents. Quarter moons are kinder to anyone with fewer than 50 dives.
- Indonesian domestic flights. Ambon, Sorong, Kaimana and Labuan Bajo are all domestic sectors, and Indonesian airline websites often reject international credit cards. I book them on Trip.com, which accepts international cards and lists every carrier: search Indonesian domestic flights on Trip.com.
My Verdict: the Best Month to Go Diving
If I had to keep one month, it would be October: hammerheads at Suanggi, Komodo still quiet, the Red Sea in season and Triton Bay about to reopen. If I had to keep one country, it would be Indonesia, because between Raja Ampat, Komodo, the Banda Sea, Triton Bay, Halmahera and Bali you can dive a world-class region in every month of the year without changing your visa. And if you are planning a first big trip and can choose your dates, aim for December to March in the Maldives or January to February in Raja Ampat: calm water, the clearest visibility of the year and sharks or mantas on most dives.
Frequently Asked Questions
Where is the best diving in October and November?
The Banda Sea in Indonesia, where late September to November is hammerhead season and October is the peak; I saw more than 200 in a week on the Sea Safari 6. For reef sharks and good visibility in the same months, Komodo in October (before the boats leave), the Red Sea’s autumn window and Raja Ampat from November.
Where should I dive in January?
Raja Ampat, where January and February bring the clearest water and the best access to Misool’s manta stations, or the Maldives, in the calm north-east monsoon with sharks lined up in the channels.
What is the best diving in March?
The Galapagos: I dived Wolf and Darwin in March 2024 for schooling hammerheads and oceanic mantas. Tubbataha opens in mid-March, and the Red Sea’s spring season begins.
Where is the best diving in July?
Bali’s Nusa Penida for the start of mola mola season, with Menjangan at its clearest. Avoid Komodo in July if you can; I counted about 50 boats in the park in July 2026.
When is the best time to dive the Galapagos?
December to May for warmer water, calmer seas and the densest hammerhead schools. I went in March. There is no bad month; June to November is colder and rougher but brings whale sharks to Darwin.
When is the best time to dive Raja Ampat?
October to April. January and February have the clearest water and the easiest Misool access; mantas peak from November to April.
When is the best time to dive the Maldives?
December to April for calm seas and the clearest channel diving; August to October for Hanifaru Bay’s feeding mantas, on a big, stable boat.
When is the best time to dive Komodo?
May, June, September and October. Mantas peak in the south from December to February with lower visibility. July and August are the busiest months.
When is the best time to dive Belize?
March to June, the calm dry season before hurricanes, which is when the outer atolls and the Great Blue Hole dive best.
When is Tubbataha open?
Only from about mid-March to mid-June. Boats sell out more than a year ahead; I went in June on the Infiniti.
Which dive destinations are good all year?
Cocos Island for hammerheads, Bali’s Tulamben and Amed coast for easy diving, and Komodo if you accept lower visibility in the manta months.
Where can I dive in the Maldives in August?
You can, but my August weeks were the roughest I have had there, with White Pearl sheltering for five nights in 2024. Go in August only for Hanifaru Bay’s mantas, and choose a large boat.
Where is the best diving in December?
The Maldives, in the calm north-east monsoon: in December 2025 I counted more than 100 sharks and around 20 eagle rays on one dive at Miyaru Kandu. Raja Ampat is the back-up, with the mantas back and most of Indonesia’s best boats in the archipelago.
Where is the best diving in February?
Raja Ampat, at its clearest. The Galapagos warm season and Socorro’s humpbacks and giant mantas are the alternatives, and Triton Bay is open: on my January–February 2019 trip, five whale sharks fed together under the Bitsjara Bay platforms.
What is the best month to see hammerheads?
October in the Banda Sea, where I saw more than 200 in a week. March for Wolf and Darwin in the Galapagos, and any month at Cocos Island, where I counted more than 70 on my first day of diving in April.
What is the best month to see manta rays?
It depends where: January in Raja Ampat, where more than 15 stayed with us at Magic Mountain; May at Nusa Penida’s Manta Point; September at Hanifaru Bay, with trains of 20 or more; and December to February in Komodo’s south.
What is the best month to see whale sharks?
October to April in Triton Bay, where I saw five together under the fishing platforms, and August to November in the Sea of Cortez. In the Maldives, South Ari has them year-round.
What wetsuit do I need for diving by month?
It depends on the month more than the destination: a 3 mm in the Maldives in December (27–30°C), a 5 mm and a hood at Nusa Penida in mola season (18–22°C at depth), and a 7 mm in the Galapagos in March, when the thermocline dropped to 14°C.
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Every month in this calendar is drawn from my own dives. Read more about how I review, or visit my Work With Me page.
