Similan Islands Diving Safety
What Every Diver Should Know Before Diving Thailand’s Most Famous Marine Park
At Big Blue Diving Khao Lak, we often receive questions about why we ask divers for certification cards, logbooks, insurance documents, and medical forms before they join a trip.
The Similan Islands are widely considered the best scuba diving destination in Thailand and one of the top dive locations in the world. Located in the Andaman Sea approximately 70 km from Khao Lak, the islands are famous for their giant granite boulders, clear water, manta rays, whale sharks, and thriving coral reefs.
Every year thousands of divers travel to Thailand specifically to experience Similan Islands scuba diving.
But what many divers don’t realise before arriving is that diving in the Similan Islands also comes with important safety requirements and documentation.
At Big Blue Diving Khao Lak, we often receive questions about why we ask divers for certification cards, logbooks, insurance documents, and medical forms before they join a trip.
The answer is simple.
These requirements exist to protect divers, crew, and the marine environment, and they are a core part of maintaining safe diving operations in one of Thailand’s most remote national marine parks.
They are also one of the reasons we are proud to maintain more than 20 years of diving operations without a serious incident.
Why Safety Matters When Diving the Similan Islands
The Similan Islands are not typical shallow reef dives.
While the marine life and scenery are spectacular, conditions can also include:
- Strong currents
- Deep dive sites
- Open ocean exposure
- Remote offshore locations
- Limited access to immediate medical facilities
Because of this, responsible dive operators follow strict safety standards recommended by international organisations such as SSI, and Divers Alert Network (DAN).
According to DAN safety reports, many diving incidents occur when divers:
- Dive beyond their training level
- Haven’t dived recently
- Have underlying medical conditions
- Lack emergency diving insurance
Proper verification and preparation dramatically reduces these risks.
This is why reputable dive centres operating in the Similan Islands National Marine Park require divers to complete a few simple steps before diving.
Similan Islands Diving Requirements: What Divers Need Before Joining a Trip
If you are joining a Similan Islands day trip or Similan liveaboard from Khao Lak, including trips aboard vessels such as the MV Blue Dolphin and MV Waverider, you should expect to provide the following documentation.
Diving Certification Card
All divers must present proof of certification.
Accepted forms include:
- Physical certification cards
- Digital certification via training agency apps such as SSI or other agencies
Certification verification ensures that divers participate only in dives that match their training level and experience.
For example:
- Open Water Divers are typically limited to 18 metres
- Advanced Open Water divers may dive to 30 metres depending on conditions
Matching diver experience to site conditions is a fundamental principle of safe scuba diving operations worldwide.
Dive Logbook and Recent Diving Experience
Your dive logbook helps dive professionals assess your experience and comfort level in the water.
At Big Blue Diving Khao Lak as a general guideline, if you haven’t dived with the boundaries below we ask for you to complete a Scuba Skills Update or a “refresher”
- 4-30 dives, not dived within 6 months
- 30-100 dives, not dived within 12 months
- 100 + dives, not dived within 12-18 months
This is for you, to feel safe and comfortable in your gear, but also for the consideration of other guests diving with us.
Refresher dives help divers review essential skills including:
Buoyancy control | Mask clearing | Emergency air sharing | Equipment set-up
According to major training organisations, divers who haven’t been in the water recently are more likely to experience stress or skill-related issues underwater. A quick refresher can make a huge difference in enjoyment and safety.
Dive Insurance (Mandatory for Diving in Thailand)
Another requirement for Similan Islands diving trips is personal diving accident insurance.
While scuba diving is statistically very safe, treatment for diving injuries can be extremely expensive.
Emergency response in remote areas may involve:
- Speedboat evacuation
- Hospital treatment
- Hyperbaric chamber therapy
Organisations such as Divers Alert Network (DAN) exist specifically to support divers in these situations.
For this reason, dive insurance is strongly recommended — and often required — for dive trips in Thailand.
If you do not have your own policy, Big Blue Diving Khao Lak can arrange temporary dive insurance coverage for your trip, typically costing 300–1900 THB depending on trip duration.
Scuba Diving Medical Questionnaire
Before diving, all divers must complete the standard Recreational Scuba Diving Medical Questionnaire used by training agencies worldwide.
If you answer “Yes” to any medical conditions, a doctor’s clearance may be required before diving.
Before diving, all divers must complete the standard Recreational Scuba Diving Medical Questionnaire used by training agencies worldwide.
If you answer “Yes” to any medical conditions, a doctor’s clearance may be required before diving.
These guidelines were developed in cooperation with the Undersea and Hyperbaric Medical Society (UHMS) and diving medicine specialists.
Medical screening helps prevent diving incidents related to:
- Heart conditions
- Lung problems
- Certain medications
- Recent injuries or surgery
This process ensures divers are fit to dive safely.
Liability Release and Assumption of Risk Forms
Professional dive centres worldwide require divers to sign liability release and assumption of risk agreements.
These documents confirm that divers:
- Understand the inherent risks of scuba diving
- Agree to follow dive briefings and safety procedures
- Will dive within their certification limits
This is standard practice across the global dive industry.
Big Blue Diving Khao Lak
Over 20 Years of Safe Similan Islands Diving
Our team has guided thousands of divers through these incredible marine parks, and we are proud to maintain more than 20 years of diving operations without a serious incident.
How to Choose a Safe Similan Islands Dive Operator
If you are planning to dive the Similan Islands, choosing the right operator is extremely important.
A reputable Similan Islands dive centre should always:
- Verify diver certifications
- Check recent diving experience
- Require medical screening
- Ensure divers have insurance
- Provide thorough dive briefings
- Maintain properly serviced equipment
- Follow Thai maritime and national park regulations
Operators that skip these steps may appear more convenient, but they are not prioritising diver safety.
When diving in remote locations like the Similan Islands, professionalism and preparation matter.
Big Blue Diving Khao Lak:
Over 20 Years of Safe Similan Islands Diving
At Big Blue Diving Khao Lak, we have been diving the Similan and Surin Islands for over two decades.
Our team has guided thousands of divers through these incredible marine parks, and we are proud to maintain more than 20 years of diving operations without a serious incident.
We believe this record comes down to three things:
Experience
Our instructors and dive guides are highly trained professionals with extensive knowledge of the local dive sites.
Professional Standards
We follow international training agency guidelines and Thai maritime safety regulations.
A Strong Safety Culture
From equipment maintenance to diver briefings and documentation checks, safety is always our priority.
The paperwork required before diving is simply part of maintaining these standards.
The Reward: Some of the Best Diving in the World
Once everything is ready and you head out to sea, the reward is unforgettable.
Diving the Similan Islands National Marine Park offers:
- Massive granite boulder formations
- Swim-through caves and pinnacles
- Huge schools of tropical fish
- Reef sharks, manta rays, and whale sharks
- Exceptional visibility in the Andaman Sea
It is easy to see why divers travel from around the world to experience Similan Islands scuba diving from Khao Lak.
Dive the Similan Islands Safely
Scuba diving should always be safe, professional, and responsibly managed.
At Big Blue Diving Khao Lak, our goal is to provide world-class diving experiences while maintaining the highest safety standards in Thailand.
We appreciate divers who understand the importance of preparation and responsible diving.
It is one of the reasons we have been able to maintain over 20 years of safe diving operations in the Similan Islands.
And we look forward to sharing these incredible dive sites with you soon.