Is Secret Reef suitable for beginner divers?

Yes! Secret Reef is perfect for beginners with a maximum depth of 12 meters. It's ideal for Open Water Divers and fun dives.

What marine life can I see at Secret Reef?

Secret Reef features colorful soft corals, nudibranchs, stingrays, reef fish, lionfish, and various crustaceans in shallow canyons.

How deep is Secret Reef?

Secret Reef has a maximum depth of 12 meters, making it accessible for all certification levels including beginners.

Why is it called Secret Reef?

Secret Reef is a hidden gem that's less crowded than other dive sites near Koh Chang, offering a peaceful diving experience with beautiful coral formations.

Can I do a try dive at Secret Reef?

Yes! The shallow depth and calm conditions make Secret Reef an excellent choice for try dives and discover scuba experiences.

Secret Reef – Hidden Dive Site Near Hin Raab South, Koh Chang

Discover Secret Reef – Koh Chang's Hidden Underwater Treasure

Picture descending into a hidden coral canyon where whip corals sway in the current, colorful nudibranchs dot every surface, and blue-spotted stingrays glide over the sandy bottom. Welcome to Secret Reef – one of Koh Chang's most enchanting dive sites, located right next to Hin Raab South. These two reefs are connected, forming one large and diverse underwater ecosystem that rewards patient explorers with macro treasures and peaceful canyon swims.

What makes Secret Reef special is its versatility. At just 12 meters maximum depth and a shallow plateau of 5–6 meters, it's perfect for Open Water divers, try dives, and anyone who loves relaxed exploration. The site features beautiful canyons that lead you over the reef, past whip corals, flower corals, and spiny cabbage corals. Divers often discover a mysterious ancient teapot and scattered gunship bullets – reminders of the area's history. The reef is less crowded than other sites, offering a peaceful, intimate diving experience.

Secret Reef is a macro paradise. Keep your eyes open for nudibranchs in every color, blue-spotted stingrays resting on the sand, moray eels peering from crevices, and barracudas patrolling the edges. The vibrant coral gardens create a living backdrop for photographers and marine life enthusiasts. Combined with Hin Raab South, the two reefs offer about 2 hours of bottom time for those who want to explore every corner. Whether you're on your first dive or your hundredth, Secret Reef delivers a memorable underwater adventure.

Why Dive at Secret Reef?

Underwater Adventure: Follow a canyon that leads you over the reef and explore a mysterious ancient teapot and scattered gunship bullets.
Marine Life: Spot barracudas, moray eels, blue-spotted stingrays, nudibranchs, and an array of tropical fish.
Vibrant Coral Gardens: Discover whip corals, flower corals, and spiny cabbage corals as you make your way through the reef.

Dive Site Overview

Max Depth	12 meters
Shallow Depth	5–6 meters
Marine Life	Barracudas, moray eels, blue-spotted stingrays, nudibranchs, whip corals, flower corals, cabbage corals

Discover the mystery of the ancient teapot and explore the stunning coral gardens of Secret Reef. Book a fun dive or scuba diving course with Chang Diving Center today!

Hard corals and whip corals at Secret Reef – coral canyon Koh Chang, Thailand

Reef fish swimming through Secret Reef canyon – Koh Chang dive site

Secret Reef coral garden – nudibranchs and marine life, Koh Chang Thailand

Scuba diver exploring Secret Reef – coral canyon diving Koh Chang, Thailand

Diver Level for this dive site.

Min. certification level: Junior, Open Water Diver (or equalled) Try Diving possibility: Yes Snorkelling possibility: Not Recommended

Dive Briefing Example for Dive Professionals – Secret Reef

This is a comprehensive dive briefing template/example for dive professionals. Use this as a reference guide to structure your own briefings. Customize the placeholders (marked with square brackets) with your specific information, guide names, and current conditions. This ensures a safe, organized, and professional dive briefing experience.

1. Dive Site Name & Introduction

Hello everyone and welcome to Secret Reef! Secret Reef is one of Koh Chang's most enchanting dive sites – a hidden coral canyon at just 12 meters maximum depth, connected to Hin Raab South. It's perfect for Open Water divers, try dives, and macro lovers. The site features beautiful canyons, whip corals, flower corals, and cabbage corals, plus nudibranchs, blue-spotted stingrays, barracudas, and moray eels.

My name is [Your Name] and I will be your dive guide today. Secret Reef is located right next to Hin Raab South – we often combine both reefs for a two-dive day. Together they offer about 2 hours of bottom time for full exploration.

2. Site Description & Dive Route

We have good conditions today at Secret Reef. The reef features canyons, a shallow plateau, and vibrant coral gardens.

Maximum Depth: 12 meters
Shallow Depth: 5–6 meters (plateau area)
Dive Route: We'll descend along the mooring line to approximately 12 meters. From there, we'll follow the canyon that leads over the reef. Explore the coral gardens, look for the ancient teapot and scattered bullets – unique site features. The shallow plateau at 5–6 meters is perfect for extended bottom time. Return to the mooring line for our safety stop.
Site Features: Coral canyon, connected to Hin Raab South, whip corals, flower corals, cabbage corals, ancient teapot, gunship bullets.
Weather Conditions: [Current conditions - e.g. "Clear water, good visibility, minimal current"]

What You Can See at Secret Reef

Secret Reef is a macro paradise. During your dive, look for:

Nudibranchs – colorful and abundant throughout the reef
Blue-spotted stingrays – often resting on the sandy bottom
Moray eels – peering from crevices and coral formations
Barracudas – patrolling the reef edges
Whip corals, flower corals, cabbage corals – the site's signature coral formations

For a complete guide to marine life in Koh Chang, check our Marine Life Guide.

3. Your Guide's Role & Positioning

I will be leading this dive and wearing [Color] and [Color] fins with a [Description of equipment/identifying feature]. You can easily identify me by [specific visual identifier - e.g. "my bright yellow BCD with the Chang Diving logo"].

[If applicable] Our Divemaster [Name] will be positioned at the back of the group, keeping an eye on everyone. [Name] will be wearing [Color] fins and will use [signal device - e.g. "this tank banger"] to get your attention if needed.

Important: Stay close to the group and maintain visual contact with your buddy and guide at all times. If you need to communicate, use standard hand signals or get my attention by tapping on your tank.

4. Entry & Exit Techniques

Boat Entry (Giant Stride)

We'll enter the water from the side of the dive boat with a Giant Stride. Here's what you should remember:

Pre-Dive Safety Check: Complete your BIG WHALES REALLY ARE FUN check before entering the water
BCD Inflation: Fully inflate your BCD before entry
Regulator: Keep your regulator in your mouth
Mask: Make sure your mask is properly fitted
Entry: Step forward with one leg, then the other, keeping legs together
After Entry: Clear the area immediately, signal OK, and swim to the mooring line

Boat Exit (Ladder)

After completing your safety stop and surfacing:

Swim back to the ladder on the side of the boat
Stand on the ladder and remove your fins (hand them to the crew)
Climb up the ladder with your regulator still in your mouth
CRITICAL: Never position yourself directly under another diver climbing the ladder
Once on deck, move away from the entry/exit area

Dinghy Entry (Backroll)

If we're using a dinghy, we'll enter with a backroll entry:

Sit on the edge of the dinghy with your back to the water
Complete your pre-dive safety check
Hold your mask and regulator in place
On three, lean back and roll into the water
Clear the area and signal OK

5. Dive Procedures & Turn-Around Points

To ensure we have enough air for a safe return and safety stop:

Turn-Around Point: We'll turn the dive around when you reach 130 bar (or 1900 PSI). This gives us more than enough air reserve to safely return to the mooring line and complete our safety stop.
Air Monitoring: Check your air gauge frequently throughout the dive. Don't wait until you're low on air to signal – communicate early!
Safety Stop: At 5 meters depth, we'll conduct a 3-minute safety stop at the mooring line before surfacing.
No-Decompression Limits: At 12 meters depth, we'll keep the dive well within safe limits.

Remember: The most important rule in diving is to never hold your breath. Breathe normally and continuously throughout the entire dive.

6. Emergency Procedures

While we don't expect any problems, it's important that everyone knows what to do in an emergency:

Buddy Separation

If you become separated from your buddy, search for 1 minute while staying at the same depth
If you can't find your buddy, make a controlled safety ascent to the surface
Wait at the surface – we'll reunite there
DO NOT continue diving alone

Out of Air / Low on Air

Low on Air: Signal immediately – we'll end the dive and ascend together
Out of Air: Signal "out of air" and use your buddy's alternate air source or make a controlled emergency swimming ascent (CESA)
Always signal problems early – don't wait until it's an emergency!

Emergency Contacts & Equipment

Police: 191
Tourist Police: 1155
Emergency Medical Service: 1669
DAN International: +1-919-684-9111 (24/7 emergency hotline for dive emergencies)
Recompression Chamber: Koh Chang Hospital, Phone: 039 521-657 or 039 586-131
Suspected DCS: See our DCS Field Evaluation Slate (PDF) for assessment procedures
Emergency Oxygen: Located in the transport box on the right of the captain's seat in the captain's cabin
First Aid Kit: Located in the transport box on the right of the captain's seat in the captain's cabin
Emergency Action Plan: For detailed emergency procedures, see our Emergency Plan Guide

7. Hand Signal Review

Hand signals can vary between countries and certification agencies, so let's make sure we're all on the same page. Here are the essential signals we'll be using today:

OK: [Description/visual] - Used to ask "Are you OK?" and respond "I'm OK"
Problem: [Description/visual] - Hand waved side to side to indicate a problem
Up: [Description/visual] - Thumbs up means "I want to go up"
Down: [Description/visual] - Thumbs down means "I want to go down"
Air Pressure: [Description/visual] - Show numbers with fingers (e.g. "I have 120 bar")
Low on Air: [Description/visual] - Hand across throat
Out of Air: [Description/visual] - Hand across throat, then point to regulator
Safety Stop: [Description/visual] - Hand horizontal, palm down, at 5 meters
Stop/Hold: [Description/visual] - Hand up, palm forward
Look/Point: [Description/visual] - Point at something interesting

Practice Question: Can you show me how you would communicate that you still have 120 bar of air pressure?

📋 Download Complete Hand Signal Guide (PDF)

8. Roster & Buddy Check (Pairing)

Let's make sure everyone is here and properly paired:

Roster Check: [Go through names] - Is everyone here?
Buddy Pairs:
- [Name] and [Name] - you'll be buddies
- [Name] and [Name] - you'll be buddies
- [Name] - you'll be my buddy today (for less experienced divers)
Buddy Check: Before entering the water, do a final check with your buddy – make sure all equipment is secure and functioning

Note: Buddy pairs are typically matched by experience level and certification. If you'd like to dive with a specific person, let me know now.

9. Environmental Awareness & Marine Hazards

Secret Reef is a protected dive site, and we must respect the marine environment:

General Rule: Look but don't touch. Avoid contact with all marine life, including corals and fish
Marine Life to Be Aware Of:
- Blue-spotted stingrays: Venomous spine on the tail – maintain respectful distance, never touch or step on
- Moray eels: Can bite if provoked – observe from a distance, never put hands in crevices
- Whip corals: Fragile – excellent buoyancy control is essential to avoid damage
- Nudibranchs: Small and delicate – observe from a distance, avoid touching
- Fire coral: Can cause skin irritation – avoid contact
Buoyancy Control: Maintain excellent buoyancy to avoid damaging corals or stirring up sediment
Conservation: Take only photos, leave only bubbles. Never remove anything from the reef

10. Pre-Dive Safety Check

Before every dive, we use the acronym "BIG WHALES REALLY ARE FUN" to make sure nothing is forgotten. For a detailed guide on why safety checks are important and how to do them correctly, check out our Safety Check Guide:

B - BCD: Check that your BCD inflates and deflates correctly. Test the power inflator and dump valves.
I - Inflation: Make sure your BCD fits properly and all straps are secure.
G - Gauges: Check your SPG (submersible pressure gauge), depth gauge, and computer. Make sure they're working and readable.
W - Weights: Check that your weight belt or integrated weights are secure and properly positioned.
H - Hose: Check all hoses for kinks or damage. Make sure your regulator hoses are routed correctly.
A - Air: Turn on your air, check your tank pressure, and take 2-3 breaths from your regulator.
L - Releases: Test all quick releases on your BCD, weight system, and any other equipment.
E - Everything: Check once more that everything is in place and working.
S - Snaps: Make sure all buckles and fasteners are secure.
R - Releases: (Second check) Verify that all releases are functioning.
E - Everything: Final check – is everything ready?
A - Air: Final air check – regulator working, tank pressure good.
L - Look: Look around – is your buddy ready? Is the entry area clear?
L - Listen: Listen for final instructions from your guide.
Y - You: Are YOU ready? Take a deep breath, relax, and enjoy the dive!
A - Again: One more quick check – everything safe?
R - Ready: Are you ready to dive?
E - Everything: Final everything check.
F - Fun: Remember – diving is FUN! Relax and enjoy!
U - Underwater: Ready to go underwater?
N - Now: Let's dive NOW!

Pro Tip: Do this check with your buddy. It's a great way to catch problems before entering the water and helps build confidence.

📋 Quick Briefing Checklist

✅ Site name and conditions understood
✅ Dive route and depths clear
✅ Guide identification confirmed
✅ Entry/exit procedures reviewed
✅ Turn-around points and air reserves understood
✅ Emergency procedures clear
✅ Hand signals reviewed
✅ Buddy paired and checked
✅ Environmental awareness discussed
✅ Pre-dive safety check completed

Questions? If you have any questions or concerns, please ask now - I'm here to help! Remember, there are no stupid questions when it comes to dive safety. Let's have a safe and amazing dive! 🌊🤿

📝 After Your Dive: Log Your Experience

Don't forget to log your dive! Your dive logbook is an important record of your diving experience and is required for many advanced courses. Whether you use a digital app or a traditional logbook, make sure to record:

Date and location
Dive site name (Secret Reef)
Maximum depth and dive duration
Air consumption (start and end pressure)
Your buddy and guide
Highlights (nudibranchs, stingrays, whip corals, canyon, etc.)

For more information on why dive logbooks are important and what to include, check out our Dive Logbook Guide. You can find the dive site stamp and get your logbook signed by your guide at the coffee station on the boat.