Diving in Thailand in November

Conditions in November

November marks a magical transition in Thailand's diving calendar, especially on the Andaman Sea side. It's when the southwest monsoon gives way to the northeast monsoon, bringing with it calmer seas and clearer waters that make for truly exceptional diving. Generally, you can expect the weather to be gorgeous with plenty of sunshine and very little rain, making surface intervals just as enjoyable as the dives themselves. This shift effectively reopens many of the prime dive sites that might have been less accessible or rougher during the preceding months.

Sea conditions in November are typically excellent, with calm waters making for comfortable boat rides and easy entries and exits. This is a welcome change after the choppier conditions of the monsoon season. Water temperatures are wonderfully warm, hovering consistently between 28-29°C (82-84°F), so you'll be perfectly comfortable even on longer dives. Visibility is generally excellent across the Andaman Sea, often reaching upwards of 25-30 meters, creating stunning panoramic underwater vistas. While currents can naturally vary by specific dive site and tidal movements, November generally offers manageable conditions, suitable for a wide range of diving experiences.

What you will see

November is an absolutely prime month for marine life sightings in Thailand, especially for those seeking out larger pelagic species. This is when the plankton blooms, fueled by the changing monsoon, attract an abundance of life to the Andaman Sea. You'll have a fantastic chance of encountering majestic manta rays, especially around cleaning stations. These gentle giants are a major draw, gliding gracefully through the water, often curious about divers. Whale sharks, though always a matter of luck, also start to make more frequent appearances as November progresses, feasting on the rich plankton. Keep your eyes peeled on both deep blue and shallow reefs for these incredible encounters.

Beyond the big stuff, Thailand's reefs are teeming with biodiversity in November. You'll be delighted by schools of colorful reef fish like fusiliers, snappers, and barracuda swirling around the coral formations. Look closely and you'll discover a vibrant macro world featuring ornate ghost pipefish, various species of seahorses, frogfish camouflaged against sponges, and an incredible array of nudibranchs in every color imaginable. Leopard sharks are also a common and beautiful sight, often found resting on sandy bottoms. The healthy hard and soft corals are at their peak, providing a stunning backdrop to all this activity.

November also marks the beginning of the high season for many species, meaning aggregations are becoming more common. You might witness large schools of reef fish, giant trevally, and dogtooth tuna patrolling the drop-offs, providing exhilarating action. The sheer volume and variety of marine life during this month truly make it one of the best times to experience the underwater wonders of Thailand.

Top dive sites this month

For a truly iconic diving experience in November, you absolutely must consider the Similan Islands and Richelieu Rock. The Similans, a national marine park, officially open in November and immediately deliver world-class diving. Sites like East of Eden, Elephant Head Rock, and Koh Bon are fantastic for both reef exploration and manta ray encounters. Just a bit further north, Richelieu Rock is consistently hailed as one of Thailand's top dive sites, and for good reason, it's a magnet for whale sharks, giant barracuda, and an unbelievable array of macro life, all centered around a vibrant pinnacle. The clear waters and rich food sources in November make these sites come alive.

Another unmissable destination in November is the Surin Islands, and particularly its famous Hin Daeng and Hin Muang sites. These two pinnacles are renowned for their spectacular soft coral gardens, massive schools of fish, and frequent sightings of manta rays and even whale sharks. Hin Daeng, the deepest drop-off in Thailand, and Hin Muang, famed for its purple corals, are absolutely bursting with life during this period. For those looking for something slightly different on the southern Andaman coast, sites around Koh Lanta offer beautiful coral gardens and a less crowded experience, with chances of leopard sharks and other reef residents.

Practical tips for your trip

Given the balmy water temperatures of 28-29°C (82-84°F), a 3mm shorty or even just a rash guard will be perfectly sufficient for most divers. If you tend to get cold easily or are planning multiple dives a day, a full 3mm wetsuit will offer extra comfort. November is fantastic for divers of all experience levels. The generally calm conditions and excellent visibility make it perfect for beginners and those looking to gain confidence, while the abundant pelagic sightings and diverse reefs offer plenty for advanced divers to explore. This is also the official start to the high season, so while boats are restarting their schedules, it's quickly becoming busy.

Liveaboard availability in November is generally good at the start of the month, but it fills up fast as the month progresses and word gets out about the fantastic conditions. It's highly recommended to book your liveaboard trip well in advance, especially if you're targeting specific boats or itineraries to the Similans and Surins. Beyond your diving gear, make sure to pack light, breathable clothing, plenty of reef-safe sunscreen, a good hat, and sunglasses. Don't forget your camera for those incredible underwater and topside shots! Be aware that some marine parks have restrictions on single-use plastics, so bringing a reusable water bottle is a good idea. The only real 'downside' to November is that you'll quickly wish you'd booked a longer trip once you experience the diving!