The quick take 2024 was tough on Thailand’s reefs. Sea temperatures ran hot, and many shallow corals bleached. In 2025, things look calmer. Heat stress has eased, and we’re seeing healthier color and new growth in many spots. On Koh Tao, we’re diving—picking sites with the best shelter and visibility each day. We’ll keep it simple, keep it safe, and keep you updated. What happened in 2024 (and why it mattered) Last year, parts of the Gulf of Thailand hit record sea temperatures, and widespread bleaching followed—especially in shallower areas. It was one of the strongest heating events on record for the region, and it made headlines for good reason. Corals can survive a warm spell, but when it lasts too long, they lose their color (bleach) and can die if stress continues. Where things stand now (2025) This year is different. Regional heat stress over the Eastern Gulf has eased back to “no stress” levels on NOAA’s gauges, which is a strong sign that conditions are far more comfortable for corals than during the 2024 peak. Nationwide, reports through early–mid 2025 describe corals that bleached last year now showing mixed outcomes: some shallow colonies suffered partial mortality, while many deeper or more sheltered sites kept color or rebounded as waters cooled. Several Thai outlets highlighted encouraging recovery notes this spring, with deeper reefs faring best. Koh Tao: what we’re seeing and how we dive We’re still diving daily. We choose sites for shelter and visibility. If one side of the island is choppy or milky, we switch to the leeward side. Simple. Shallow vs deeper: After big heat spikes, shallow corals can look patchy. Deeper and shaded areas often look better. Your guide will brief the plan and what to expect. Wildlife vibes: Reef fish, rays, and schooling action remain great. Expect the usual batfish-at-safety-stop moments, plus plenty of life doing “reef life” things. A realistic (but positive) outlook Bleaching is not a light switch; recovery takes time. The good news is that stable, cooler conditions give stressed corals a better chance to bounce back. As always, the outlook depends on weather and heat trends, but right now the data is far friendlier than last year’s peak. We’ll keep watching official monitoring and adjust our plans as needed. How Phoenix Divers adapts when weather or visibility changes Site selection: We read wind, swell, and currents and pick protected reefs or pinnacles accordingly. Timing: We use calm windows and tide turns for easier entries and clearer water. Plan B ready: If a site looks off when we arrive, we swap to our backup. Comfort beats bragging rights. What you can do to help reefs while you dive Perfect your buoyancy: Fins up, frog kicks if you can, and no touching. The less contact, the better the reef does. Reef-safe habits: Apply reef-friendly sunscreen before the boat and use rash guards to reduce lotion use. Thailand is actively promoting coral-safe products in 2025—small choices add up. Follow the guide: We’ll brief fragile patches and the best routes. A little awareness goes a long way. Answers to questions we’re hearing right now Is Koh Tao open for diving? Yes. We’re running trips and courses as normal, with daily site selection based on conditions. Will visibility be okay? It varies after storms, but often settles quickly. We’ll chase the best water on the day. Can I still see healthy coral? Absolutely—especially on deeper or well-sheltered routes. Recovery and new growth are out there. Where can I follow official updates? Thailand’s marine agency (DMCR) maintains a public bleaching portal; scientists and NOAA also publish ongoing heat-stress indicators. We use these sources to sanity-check what we see on our dives. Planning your trip Stay flexible: If wind or rain pops up, we may tweak schedules or sites for comfort. Ask us about seasons: We’ll explain typical visibility, temperatures, and site choices across the year. Make it meaningful: Want to do more? Add Perfect Buoyancy or Naturalist, or join a reef-clean or monitoring dive when available. Final word: calm seas ahead Last year’s bleaching was real and it hurt, especially in shallow water. This year’s picture is calmer, and many reefs around Koh Tao are looking better again. We’re optimistic, but we stay honest—if a site needs a rest, we let it rest. If the other side of the island looks dreamy, we go there instead. Either way, we’ll find you good water and a relaxed day out. Come dive with usWe keep groups small, plans simple, and briefings clear. Tell us your experience level and dates, and we’ll shape a dive plan that feels great now—and supports the reef long term. Message Phoenix Divers and we’ll get you in the water.Get in touch