Scuba diving cost in the Similan Islands: liveaboards, national park fees & the season
The Similans are Thailand's premier liveaboard diving — granite boulders, manta and whale shark country, open only half the year. Here's the honest all-in cost, including the park fee.
The Similan Islands, in the Andaman Sea off Thailand's west coast, are the country's premier liveaboard destination — a chain of granite-boulder islands and reefs that look more like an underwater sculpture park than typical tropical diving. North of the Similans proper lie the famous sites of Koh Bon, Koh Tachai and Richelieu Rock, where mantas and seasonal whale sharks appear. The whole area is a national marine park, and that brings two defining features: a mandatory park fee, and a strict season. Here's what diving the Similans really costs in 2026.
Why the Similans are liveaboard-first
The Similans sit well offshore, and the best sites — especially Richelieu Rock, far to the north — are a long way out. While day-trip speedboats run from Khao Lak, the classic way to dive the Similans is a liveaboard, typically 3 to 5 nights out of Khao Lak or Phuket, hitting four dives a day and reaching the northern pinnacles that day boats struggle to. The liveaboard is where the value and the best diving concentrate; day trips are long and dive fewer sites.
The national park fee is mandatory and usually extra
The Similan and Surin national parks charge an entry fee for divers, often levied per day or per entry, and it is usually NOT included in the liveaboard or day-trip price you are quoted. Over a multi-day liveaboard it is a real line item. Always ask whether the park fee is included and check live verified prices on DiveCost.
Liveaboard pricing from Khao Lak
Similan liveaboards are mid-range by global standards — far cheaper than the Galápagos or Palau, more than a day-trip habit on Koh Tao. As an indicative range, a 3- to 4-night liveaboard commonly falls somewhere around US$500–$1,200+ per person depending on the boat's standard and cabin. That typically bundles cabin, all meals, multiple guided dives a day, tanks and weights. Park fees, nitrox, gear rental, alcohol and crew gratuities sit on top.
| 3–4 night liveaboard (per person)boat & cabin dependent | ~$500–$1,200+ |
| Day-trip speedboat (from Khao Lak) | indicative, full long day |
| National park entry fee | mandatory, usually extra |
| Nitrox (per trip) | common surcharge |
| Gear rental / crew gratuities | extra, budget on top |
The season is non-negotiable
Here is the single most important cost-and-planning fact about the Similans: the national park closes for the monsoon. The diving season runs roughly mid-October to mid-May, and outside that window the park is shut and the liveaboards do not run. This compresses all demand into about seven months, which keeps high-season prices firm and the best boats booked out well ahead. If you want the Similans, you must plan around that window — there is no diving them off-season at any price.
Book early for the season — and for whale shark months
Because the park is only open roughly October to May, the good liveaboards fill up months ahead, especially over peak holidays and the manta/whale-shark windows at Koh Bon and Richelieu Rock. Booking late means higher prices or no berth at all. Plan the dates first, then compare boats.
The extras to budget for
- National park entry fee, mandatory, usually charged on top of the dive price.
- Nitrox surcharges, popular for four-dive liveaboard days.
- Gear rental if you fly light, and crew gratuities, which are customary.
- Transfers from Phuket or Khao Lak to the liveaboard pier.
- Travel and dive insurance for offshore, multi-dive-a-day trips.
If you are comparing Thailand's dive options, the Similans are the liveaboard end and Koh Tao is the budget certification end — two very different Thai trips at very different price points.
Because the Similans are liveaboard-first, read our liveaboard diving cost guide and the hidden costs of scuba diving so the park fee and gratuities don't surprise you.
The DiveCost view on the Similans
Similan liveaboard prices are reasonable for the quality, but the national park fee and the seven-month season are the two facts that catch people out. We surface the park fee separately and flag the season so you compare boats on an honest all-in basis — and book before the good ones sell out.
Bottom line: the Similan Islands are Thailand's best diving and its premier liveaboard trip — granite scenery, mantas and whale shark season, at fair mid-range prices. Add the mandatory national park fee, plan strictly around the roughly October-to-May window, and book the good boats early. Do that and the Andaman delivers some of the most rewarding diving in Southeast Asia.