Diving Thailand in July: Where to Dive and What's Closed

Featured image: Amada44, CC BY-SA 3.0, via Wikimedia Commons.

Quick answer: can you dive Thailand in July?

Yes, you can dive in July, but the coast you choose decides the trip. July is low, wet season on the Andaman (west) coast. Headline Similan liveaboards are not running. The Gulf of Thailand has its own diving season, which one dive agency describes as running March to September. Phuket and Phi Phi boats keep going on calmer days. For the year-round picture, start with our Thailand dive season overview.

• Gulf (Koh Tao, Koh Samui, Koh Pha Ngan): the main option for July, strong for courses and fun dives.
• Phuket and Phi Phi: day trips continue, but sea state can cancel or reroute boats.
• Similan Islands and other national park sites: closed for the low season.
• Verdict: worth it for course students and relaxed fun divers, not for big-pelagic chasers.

July diving in Thailand at a glance

This table compares each base for a July trip. Conditions are qualitative because rain and sea state change week to week. Check a marine forecast and your operator's daily call before committing to a boat day.

Gulf of Thailand diving in July

Koh Tao is the default base for July, because the Gulf side is in season while the west coast is wet. Dive centers on Koh Tao and Koh Samui run trips to Sail Rock, a granite pinnacle that dive operators link to Koh Pha Ngan. Chumphon Pinnacle is the other name you will see on boat schedules. Whale sharks are talked about at both sites. Treat them as a possibility, never a promise. Koh Tao also has plenty of local sites for relaxed reef dives and student training. If you are comparing neighboring months, read our June diving guide and our August diving guide to see how the Gulf holds up on either side.

Phuket, Phi Phi and Andaman day trips in July

Phuket operators keep running day trips all year. Racha Noi and Racha Yai sit south of Phuket. Phi Phi, King Cruiser Wreck and Shark Point lie east of Phuket. One Phuket operator lists three-dive itineraries for the Racha islands, Phi Phi, and the King Cruiser and Shark Point combination. Weather swings from wet and windy to sunny with short heavy showers. On bad sea days, the boat may change site or stay in port. There are no Similan day trips in low season.

• Rough sea fallback 1: ask your operator to switch to a more sheltered site on the same day.
• Rough sea fallback 2: move the dive day to the next morning and keep one spare day in your plan.
• Rough sea fallback 3: shift to the Gulf if the whole Andaman coast is restricted for several days.

What's closed in July

Similan Islands National Park is closed from about May 15 to October 15, according to Phuket operators. Closure dates are revised, so check the notices published by Thailand's Department of National Parks. Remote Andaman sites such as Richelieu Rock, Koh Bon and Koh Tachai are normally reached on liveaboard routes that serve the Similans. They are effectively out of reach in July. If those sites matter most, move your dive portion to our October diving guide or our November diving guide.

Liveaboards in July

Similan liveaboards generally run from late October to mid-May. In July, only short options remain, such as a 3-day, 2-night Phi Phi and Racha trip from Phuket. Many longer trips are cancelled for lack of numbers. If you want a full liveaboard week in Thailand, book for the high season, and reserve early for departures from October onward. For July, a resort-based Gulf trip gives more diving per baht of effort than chasing a limited summer boat.

Costs, booking and time trade-offs

Low season usually means quieter boats and easier availability, but sea-state risk rises on the Andaman side. Operators set their own rates, so request written quotes for day trips, courses and fun-dive packages. Course length also affects budget and schedule. A Phuket operator lists Discover Scuba at 1 day, Open Water Diver at 3 days, and Advanced Open Water at 2 days. Do not book a non-refundable single-day dive trip on the last day before a flight. Add at least one buffer day so a cancelled boat does not cost you the trip.

• Day trips: flexible and cheap to rebook, but weather-dependent.
• Resort-based courses: predictable schedule, best on the Gulf in July.
• Short liveaboards: limited choice, so confirm the route and cancellation terms in writing.

Who should go and who should skip

Match your trip to your priorities. The list below gives a plain verdict by diver profile.

• New diver or course student: go, with Koh Tao as the first choice.
• Certified fun diver, relaxed goals: go, split time between the Gulf and Phuket day trips.
• Diver chasing big pelagics and Similan sites: skip July and look at the January, February or March pages.
• Underwater photographer: wait, since sea state and plankton make shot lists unreliable.
• Mixed family or non-diver group: go only if beaches and rain-tolerant plans suit everyone.

Getting there and getting around

For the Andaman side, Phuket is the usual gateway. For the Gulf, travelers commonly route through Surat Thani or Koh Samui and continue by ferry to Koh Tao. Ferry timetables change, so use the current operator schedule rather than a fixed travel time. In rough seas, ferries can be delayed or cancelled. Leave a buffer day at both ends of a Koh Tao stay. Our Thailand water temperature guide covers sea conditions month by month.

Mistakes to avoid

Most July disappointments come from planning around the wrong coast.

• Booking a Similan trip: the park is closed for the low season.
• Promising yourself whale sharks or mantas: sightings are never guaranteed.
• Stacking a dive day on the last day before a flight.
• Using one coast only: keep a Gulf option if the Andaman is rough.
• Skipping a month check: neighboring months like May and September behave differently.