Koh Tao Travel Guide 2026
09 Jul 202655.6K2
Ticket2Attraction

Koh Tao is a small island located in Ko Pha-ngan District, Surat Thani Province, in the heart of the Gulf of Thailand. Situated approximately 45 kilometers north of Koh Pha-ngan, the island covers an area of around 21 square kilometers and lies close to Koh Nang Yuan, a famous island known for its stunning sandbar viewpoint and crystal-clear waters.
Today, Koh Tao is one of the world's most popular diving destinations, attracting divers from across the globe. With its clear turquoise waters, vibrant coral reefs, and more than 20 dive sites surrounding the island, Koh Tao is ideal for snorkeling, scuba diving, and freediving. Favorable sea conditions throughout most of the year have also made the island a leading center for dive education, offering numerous internationally recognized diving courses and certifications.
Beyond its natural beauty, Koh Tao also has an interesting history. Between 1943 and 1944, the island was used as a detention site for political prisoners. Afterward, settlers from Koh Samui and nearby areas moved to the island, gradually establishing a small community. Koh Tao began gaining recognition among travelers in the late 1970s and has since evolved into a world-renowned tropical destination.
Koh Tao May Be Small, but It’s Packed with Amazing Attractions
Once you arrive on Koh Tao, here’s a useful travel tip: if you plan to explore the island’s many bays, beaches, and viewpoints, renting a motorbike is one of the most convenient ways to get around. Although Koh Tao covers only about 21 square kilometers, it is home to numerous scenic spots spread across the island. Motorbike rental shops can be found in popular areas such as Sairee Beach and Mae Haad, with daily rental rates typically ranging from THB 150–300, depending on the type of bike. With your transportation sorted, it’s time to hit the road and start exploring!, From stunning viewpoints and white-sand beaches to crystal-clear waters and vibrant marine life, Koh Tao is full of unforgettable experiences. Here are some of the island’s must-visit attractions that are sure to make you fall in love with this tropical paradise. ❤️
1. Hat Sai Ri
Sairee Beach is one of the most popular and vibrant beaches on Koh Tao. Stretching for nearly 2 kilometers, the beach is lined with a wide variety of restaurants, hotels, resorts, cafés, and beachfront bars, making it a favorite gathering spot for visitors. The relaxed atmosphere makes Sairee Beach perfect for leisurely walks, sunbathing, and simply unwinding by the sea. It is also one of the best places on the island to enjoy a spectacular sunset, with breathtaking views over the Gulf of Thailand. Conveniently located just a short distance from Mae Haad Bay, Sairee Beach can be reached in approximately 10 minutes on foot, making it easily accessible for travelers staying near the island’s main pier.
2. Shark Bay
Shark Bay, also known as Ao Thian Og, is one of Koh Tao’s most important and popular snorkeling and diving spots. It is especially well known among divers and snorkelers for its rich marine life and the opportunity to observe Koh Tao’s underwater ecosystem up close. One of the highlights of Shark Bay is the chance to encounter blacktip reef sharks in their natural habitat. Despite their name, these sharks are generally shy and non-aggressive toward humans, making them a fascinating sight for visitors rather than something to fear. As much of the bay is part of a privately managed area, most visitors access Shark Bay through island-hopping, snorkeling, or diving tours by boat.
3. Mae Haad Bay
Another popular snorkeling spot on Koh Tao is Mae Haad Bay. This picturesque bay is home to a fascinating sunken coconut cargo boat that sank in 1962. Over the decades, the wreck has evolved into an artificial reef, providing shelter for a wide variety of marine life. Today, snorkelers can spot numerous species around the wreck, including yellowtail barracuda, scissortail sergeant fish, blue-spotted stingrays, and many other tropical fish waiting to be discovered beneath the surface. Mae Haad Bay is also considered one of the island’s main hubs, much like Sairee Beach, making it incredibly easy to access. Whether you're staying nearby or exploring the island by motorbike, a short ride is all it takes to reach this excellent snorkeling location and experience Koh Tao’s underwater beauty firsthand. 🐠🌊🏍️
4. Freedom Beach
Freedom Beach is one of Koh Tao’s most well-known and picturesque beaches, attracting visitors with its peaceful atmosphere and stunning coastal scenery. It is particularly popular among photographers thanks to its beautiful viewpoints and crystal-clear waters. This small and secluded beach is ideal for travelers looking to relax, unwind, and enjoy a quieter side of the island. From the shore, visitors can admire Ta Toh Rock, a distinctive rock formation located at the tip of the nearby headland, which adds to the beach’s scenic charm.
Freedom Beach is also an excellent spot for snorkeling directly from the beach. The clear waters are home to abundant marine life, and it is common to encounter large schools of colorful tropical fish swimming close to shore. Whether you're sunbathing on the sand, taking photos, or exploring the underwater world, Freedom Beach offers a relaxing and unforgettable Koh Tao experience.
5. Snorkeling Around Koh Tao
Koh Tao is often regarded as a paradise for snorkelers and divers, offering crystal-clear waters, thriving coral reefs, and an incredible diversity of marine life. Visitors can experience the island’s rich underwater ecosystem up close, making it one of the top snorkeling destinations in the Gulf of Thailand.
The warm, turquoise waters surrounding the island provide excellent visibility, allowing snorkelers to admire colorful reef fish, sea turtles, and a wide variety of fascinating marine species in their natural habitat.
Koh Tao snorkeling tour around Koh Tao and Nang Yuan Island
Enjoy a full-day snorkeling adventure around Koh Tao and visit the stunning sandbar at Koh Nang Yuan. Travel aboard a large wooden boat equipped with a waterslide, allowing you to slide directly into the crystal-clear sea and explore one of the world's most beautiful and diverse marine ecosystems. This tour is perfect for a day trip, departing in the morning and returning in the evening.
Highlights
- Visit the 5 best snorkeling spots around Koh Tao
- Travel on a spacious wooden boat that provides a more stable ride and helps reduce the impact of sea waves, making your journey more enjoyable
- Best price guarantee
- Carefully selected tour operators with professional guides and quality snorkeling equipment
- Includes lunch and hotel transfer service
Or book our Koh Tao 3 Days 2 Nights Package, which includes accommodation and round-trip ferry transfers between Chumphon and Koh Tao. Explore the island at your own pace with Ticket2Attraction’s hassle-free travel package no planning required, with assistance provided throughout your trip. Just bring a companion and start your adventure!
Koh Tao 3D2N Package Hotel and Snorkeling Tour
6. Scuba Diving Around Koh Tao
Koh Tao is one of the best places in the world to learn scuba diving, offering courses for every level, whether you're a complete beginner or an experienced diver looking to advance your skills.
The island is famous not only for its powdery white beaches and laid-back atmosphere but also for its incredible underwater world. With crystal-clear waters, colorful coral reefs, and thriving marine life, diving around Koh Tao is an experience like no other.
One of the highlights of diving here is White Rock, one of Koh Tao’s most popular dive sites. This site consists of two large rock formations surrounded by vibrant coral gardens and abundant marine life. As you swim between the rocks, you may encounter sea turtles, white-eyed moray eels, butterflyfish, angelfish, longfin bannerfish, pufferfish, golden stingrays, nudibranchs, barracudas, and large schools of tropical fish. If you're lucky, you might even spot a majestic whale shark passing through the area.
Explore 5 of the island’s most famous dive sites
| Dive Spot | Highlights |
|---|---|
| Chumphon Pinnacle | One of Koh Tao’s most famous dive sites, known for abundant marine life, large schools of fish, whale shark sightings, and beautiful pink anemones. |
| Sail Rock | Features strong currents and deep waters around a towering rock formation, attracting diverse marine life and offering exciting swim-through experiences. |
| Shark Island | Ideal for advanced divers, with healthy coral reefs, colorful tropical fish, and a fascinating sunken junk ship. |
| White Rock | The largest dive site near Koh Tao, home to stingrays, sea turtles, and moray eels. It is also one of the island’s most popular night diving locations. |
| Green Rock | Best suited for experienced deep divers, featuring caves, swim-throughs, unique marine species, and frequent sightings of green and hawksbill sea turtles. |
If you are planning a trip to Koh Tao, we highly recommend booking a 3D2N Koh Tao Try Scuba Diving package that includes a hotel, a roundtrip ferry ride to/from Chumphon, and a one-day scuba diving course for those looking to try scuba diving in Koh Tao without prior diving experience.
Scuba diving schools in Koh Tao
If you are coming to Koh Tao and looking to get your diver's license, here are some examples of scuba diving schools we highly recommend.
Koh Tao 3D2N Package Hotel + Scuba Diving (No Certificate/ 2 dives)
7. Freediving Courses : Koh Tao
Freediving has become one of the hottest water sports trends in recent years, and you've probably seen stunning underwater photos on Instagram featuring influencers and celebrities gliding effortlessly beneath the surface wearing nothing more than a mask and fins. Unlike scuba diving, freediving does not require heavy equipment such as an oxygen tank. Instead, divers rely solely on breath-holding techniques, along with basic gear like fins and a diving mask. With proper training and physical preparation, you can explore the underwater world, improve your breath-hold ability, and capture breathtaking underwater photos all while enjoying a more natural connection with the ocean. Koh Tao is one of the best places in Thailand to learn freediving, thanks to its calm waters, excellent visibility, and professional training schools catering to all skill levels.
Package Koh Tao 3D2N Hotel + Try Freediving course
Take your underwater adventures to the next level with a PADI Freediving Course on Koh Tao. Experience the freedom of exploring the ocean using only your breath while developing new skills in one of Thailand’s most popular freediving destinations. The course combines convenient e-learning theory sessions with hands-on training in both a swimming pool and the open sea. Whether you're a complete beginner or looking to improve your abilities, you can choose from three freediving courses across three certification levels, designed to help you progress safely and confidently.
8. Capture the Iconic Koh Nang Yuan Sandbar Viewpoint
Koh Nang Yuan is a small island located just off the coast of Koh Tao, only a 15–20-minute boat ride away. A visit to Koh Tao wouldn’t be complete without stopping by this iconic destination. The island’s most famous attraction is its spectacular Unseen Thailand sandbar viewpoint, where visitors can enjoy panoramic views of the unique sandbar connecting three small islands. The hike to the viewpoint is relatively easy and takes only 15–20 minutes along a well-marked trail. For those who wish to stay overnight, the island has only one accommodation option: Nangyuan Island Dive Resort. One important rule that all visitors must follow is that plastic items are prohibited on the island. Bringing a reusable water bottle is highly recommended to help preserve the island’s pristine natural environment. Beyond visiting the famous viewpoint, Koh Nang Yuan is also an excellent destination for snorkeling directly from the beach. The surrounding waters are home to both soft and hard coral reefs, along with a wide variety of colorful tropical fish and other marine life, making it a fantastic spot for anyone looking to explore the underwater world.
9. Learn Thai Cooking and Practice Yoga
Enjoy a relaxing Thai cooking class or yoga session in a laid-back beachfront setting on Koh Tao. These activities are perfect for families, travelers with children, or anyone looking for a fun and rewarding way to spend a few hours between island adventures. Both activities are especially popular among international visitors. Thai cuisine is loved worldwide for its rich flavors and unique ingredients, inspiring many travelers to learn how to prepare their favorite dishes themselves. A Thai cooking class offers a hands-on cultural experience, allowing you to create authentic recipes and take home new culinary skills. For those seeking relaxation and wellness, yoga classes provide the perfect opportunity to unwind while surrounded by Koh Tao’s beautiful natural scenery. Whether you're a beginner or an experienced practitioner, practicing yoga by the sea can be a refreshing and memorable part of your island getaway.
If you're interested in trying something new during your stay, check out the details below and discover a different side of Koh Tao beyond its beaches and underwater attractions.
- Thai cooking class Thai Cooking with Joy (Facebook Page) - yoga session Shambala Koh Tao
10. Charter a Luxury Private Wooden Boat Around Koh Tao (Snorkeling, Paddle Boarding and Stunning Photo Opportunities for Social Media)
For travelers looking for a unique experience on Koh Tao beyond the typical snorkeling tour, White Whale offers one of the island’s most memorable adventures. This luxury private wooden boat charter takes you across the crystal-clear waters surrounding Koh Tao and Koh Nang Yuan, where you can enjoy snorkeling, paddle boarding, fishing, and relaxing at sea in an exclusive setting. Designed in a sophisticated modern-classic style, the boat features beautifully crafted spaces and photogenic corners throughout the vessel, earning it the nickname “Studio on the Ocean.” It is an ideal choice for couples, groups of friends, or families seeking a peaceful and private escape without sharing the experience with other tourists. During the trip, guests can enjoy a variety of activities, including:
- Snorkeling among vibrant coral reefs
- Paddle boarding (SUP)
- Watching a breathtaking sunset at sea
- Relaxing on the spacious deck while taking in panoramic ocean views
Koh Tao Private Luxury Wooden Boat Charter by White Whale
Today, Koh Tao is widely regarded as one of the best diving destinations in Thailand, offering a perfect combination of pristine beaches, rich marine life, breathtaking natural scenery, and exciting water activities. Whether you're an adventure seeker or simply looking to relax in the peaceful atmosphere of the Gulf of Thailand, Koh Tao provides an unforgettable island experience.

Leaving from Bangkok
Traveling by Bus The final option for getting to Koh Tao via Chumphon is also one of the most convenient. Lomprayah offers a combined bus-and-ferry package from Bangkok to Koh Tao for approximately THB 1,250 per person. The service includes transportation from Bangkok to Chumphon by air-conditioned bus, followed by a high-speed ferry directly to Koh Tao.
The biggest advantage is that you only need to purchase a single ticket for the entire journey, eliminating the hassle of coordinating separate transfers or worrying about whether you'll make it to the ferry on time. Buses depart from Bangkok daily, making it a convenient and stress-free travel option.
You can click below to book your Bus + Ferry ticket from Bangkok to Koh Tao
Bus and Ferry Ticket Bangkok-Koh Tao by Lomprayah
Bus & Ferry from Bangkok to Koh Tao by Boonsiri
Bus and Ferry Schedule: Koh Tao ↔ Bangkok
Travelers can choose between Lomprayah and Boonsiri for journeys from Bangkok to Koh Tao. Both operators offer daytime and overnight departures, providing flexible travel options to suit different schedules.
| Operator | Route | Departure Time | Arrival Time |
|---|---|---|---|
| Lomprayah | Bangkok (Pinklao) → Koh Tao | 9:00 PM | 8:45 AM (next day) |
| Lomprayah | Bangkok (Khao San Road) → Koh Tao | 6:00 AM | 3:00 PM |
| Lomprayah | Bangkok (Khao San Road) → Koh Tao | 9:30 PM | 8:45 AM (next day) |
| Boonsiri | Bangkok (Khao San Road) → Koh Tao | 5:00 AM | 3:00 PM |
| Boonsiri | Bangkok (Khao San Road) → Koh Tao | 10:00 PM | 8:45 AM (next day) |
| Boonsiri | Suvarnabhumi Airport → Koh Tao | 8:00 PM | 8:45 AM (next day) |
Whether you prefer a daytime trip or an overnight journey that saves on accommodation costs, these combined bus-and-ferry services offer a convenient way to travel from Bangkok to Koh Tao with a single booking.
Traveling from Chumphon to Koh Tao
✈️ By Airplane
Flying to Chumphon is the fastest and most convenient way to reach Koh Tao, as Chumphon is the closest mainland gateway to the island. Flights from Don Mueang International Airport (DMK) to Chumphon take approximately 1 hour.
The recommended option is to take the afternoon flight and spend one night in Chumphon before taking a transfer to the ferry pier the following morning. You can check ferry schedules and additional details through the Chumphon–Koh Tao ferry ticket booking page.
🚆 By Train
Traveling to Chumphon by train is another popular option. The recommended service is Express Train No. 85, which departs from Bangkok Railway Station late at night and arrives at Chumphon Railway Station the following morning.
After arriving in Chumphon, travelers can continue to the ferry pier and catch the 8:00 AM ferry to Koh Tao. While there are several train services operating between Bangkok and Chumphon, express trains are generally recommended because they are less likely to experience delays that could cause you to miss your ferry connection.
🛳 By Ferry
There are several ferry services operating between Chumphon and Koh Tao, offering different vessel types and price ranges. The main departure point is Lomprayah Pier, the most popular ferry terminal serving the route.
Lomprayah Pier offers the fastest ferry service to Koh Tao. Its high-speed catamaran ferries take approximately 1 hour 30 minutes to 1 hour 45 minutes to reach the island. Other ferry options, such as overnight boats, typically take around 7 hours. Travelers can check ferry schedules, availability, and fares through the Chumphon to Koh Tao ferry ticket booking page.
Ferry Ticket between Chumphon and Koh Tao by Lomprayah
If you're planning to travel by overnight boat, it's a good idea to allow extra time for your journey and make sure you arrive at the pier before departure. Missing the boat means you'll have to wait for the next available sailing.
Although overnight boats take longer than high-speed ferries, the trip is generally more comfortable than many travelers expect. Sleeping berths are available on board, allowing passengers to rest during the journey. By the time you arrive in Koh Tao, you'll have had a chance to sleep and wake up feeling refreshed, ready to start exploring the island right away.
Chumphon ↔ Koh Tao Ferry Schedule
Travelers can conveniently travel between Chumphon and Koh Tao with Lomprayah High-Speed Catamaran services operating daily in both directions.
| Operator | Route | Departure Time | Arrival Time |
|---|---|---|---|
| Lomprayah | Chumphon (Thung Makham Noi Pier) → Koh Tao | 7:00 AM | 8:45 AM |
| Lomprayah | Chumphon (Thung Makham Noi Pier) → Koh Tao | 1:15 PM | 3:00 PM |
| Lomprayah | Koh Tao → Chumphon (Thung Makham Noi Pier) | 10:15 AM | 11:45 AM |
| Lomprayah | Koh Tao → Chumphon (Thung Makham Noi Pier) | 3:00 PM | 4:45 PM |
Traveling from Surat Thani to Koh Tao
✈️ By Airplane
Travelers can fly to Surat Thani Province through two airports: Surat Thani Airport (URT) and Samui International Airport (USM).
Surat Thani Airport (URT)
Several airlines operate daily flights from Bangkok to Surat Thani, with a flight time of approximately 1 hour 10 minutes. Upon arrival, travelers can continue directly to the ferry pier for their journey to Koh Tao.
One of the most popular and efficient routes is to fly into Surat Thani Airport and then travel to Donsak Pier, where ferries depart for Koh Tao. This option is widely preferred because it offers a convenient connection while helping travelers save time and transportation costs.
Ticket2Attraction also offers a convenient airport transfer service from Surat Thani Airport to Donsak Pier, making it easy to connect with your ferry to Koh Tao at a special price.
Ferry & Van from Surat Thani to Koh Tao by Boonsiri
Ferry Ticket Surat Thani (Don Sak Pier) - Koh Tao by Lomprayah
Transfer + Ferry Schedule: Koh Tao ↔ Surat Thani (Donsak Pier)
Travelers can choose between Lomprayah and Boonsiri services for travel between Surat Thani and Koh Tao. Both operators offer convenient ferry connections, with Boonsiri also providing combined transfers from Surat Thani Railway Station and Surat Thani Airport.
| Operator | Route | Departure Time | Arrival Time |
|---|---|---|---|
| Lomprayah | Surat Thani (Donsak Pier) → Koh Tao | 11:00 AM | 2:45 PM |
| Lomprayah | Surat Thani (Donsak Pier) → Koh Tao | 3:00 PM | 5:45 PM |
| Lomprayah | Koh Tao → Surat Thani (Donsak Pier) | 9:30 AM | 12:45 PM |
| Boonsiri | Surat Thani (Donsak Pier) → Koh Tao | 1:15 PM | 4:25 PM |
| Boonsiri | Surat Thani (Railway Station) → Koh Tao | 10:30 AM | 4:25 PM |
| Boonsiri | Surat Thani (Airport) → Koh Tao | 11:30 AM | 4:25 PM |
| Boonsiri | Koh Tao → Surat Thani (Donsak Pier) | 8:30 AM | 11:20 AM |
| Boonsiri | Koh Tao → Surat Thani (Railway Station) | 8:30 AM | 1:00 PM |
| Boonsiri | Koh Tao → Surat Thani (Airport) | 8:30 AM | 2:00 PM |
Traveling from Koh Samui to Koh Tao
For travelers heading from Koh Samui to Koh Tao, there are convenient high-speed ferry and speedboat services operated by Lomprayah and Seatran. The journey typically takes around 1 hour 30 minutes to 2 hours, depending on the operator and sea conditions.
Ferries depart from major piers on Koh Samui, including Maenam Pier, Nathon Pier, and Bangrak Pier, and arrive at Mae Haad Pier, the main ferry terminal and transportation hub on Koh Tao.
To make your journey smoother, it is recommended to book a ferry ticket that includes hotel pick-up and transfer service in advance. This ensures a hassle-free connection to the pier and helps you arrive on time for your ferry departure, as services operate throughout the day with multiple departures available.
Ferry Ticket Koh Samui (Nathon Pier) - Koh Tao by Lomprayah
Ferry Ticket Koh Samui (Pralarn Pier) - Koh Tao by Lomprayah
Koh Samui - Koh Tao Passenger Ferry by Laemsor Lomprayah Ferry
Transfer + Ferry Schedule: Koh Samui ↔ Koh Tao
Travelers can conveniently travel between Koh Samui and Koh Tao with Lomprayah High-Speed Catamaran services operating daily from multiple piers on Koh Samui.
| Operator | Route | Departure Time | Arrival Time |
|---|---|---|---|
| Lomprayah | Koh Samui (Nathon Pier) → Koh Tao | 12:15 PM | 2:15 PM |
| Lomprayah | Koh Samui (Nathon Pier) → Koh Tao | 4:00 PM | 5:45 PM |
| Lomprayah | Koh Samui (Pralarn Pier, Maenam) → Koh Tao | 8:00 AM | 10:00 AM |
| Lomprayah | Koh Samui (Pralarn Pier, Maenam) → Koh Tao | 12:30 PM | 2:15 PM |
| Lomprayah | Koh Tao → Koh Samui (Pralarn Pier, Maenam) | 9:30 AM | 11:30 AM |
| Lomprayah | Koh Tao → Koh Samui (Pralarn Pier, Maenam) | 3:30 PM | 5:30 PM |
| Lomprayah | Koh Samui (Maenam Pier) → Koh Tao | 11:00 AM | 1:30 PM |
| Lomprayah | Koh Tao → Koh Samui (Maenam Pier) | 4:30 PM | 7:30 PM |
Traveling from Koh Phangan to Koh Tao
Traveling from Koh Phangan to Koh Tao is easy and convenient, with the most popular option being a high-speed catamaran or speedboat departing from Thong Sala Pier on Koh Phangan. The ferry travels directly to Mae Haad Pier, the main and only ferry terminal on Koh Tao. The journey typically takes around 1 to 1.5 hours, depending on the type of vessel and weather conditions on the day of travel.
The most popular operator on this route is Lomprayah, which offers reliable and frequent services, making it a convenient choice for travelers exploring the islands of the Gulf of Thailand.
Ferry Schedule: Koh Phangan ↔ Koh Tao
Travelers can easily travel between Koh Phangan and Koh Tao with Lomprayah High-Speed Catamaran services operating daily. With journey times ranging from approximately 1 hour 15 minutes to 1 hour 40 minutes, this is one of the fastest and most convenient ways to travel between the two islands.
| Operator | Route | Departure Time | Arrival Time |
|---|---|---|---|
| Lomprayah (Laem Sor Boat) | Koh Tao → Koh Phangan | 4:30 PM | 6:10 PM |
| Lomprayah (Laem Sor Boat) | Koh Phangan → Koh Tao | 12:00 PM | 1:30 PM |
| Lomprayah | Koh Phangan → Koh Tao | 8:30 AM | 10:00 AM |
| Lomprayah | Koh Phangan → Koh Tao | 1:00 PM | 2:15 PM |
| Lomprayah | Koh Phangan → Koh Tao | 4:45 PM | 5:45 PM |
| Lomprayah | Koh Tao → Koh Phangan | 9:15 AM | 10:30 AM |
| Lomprayah | Koh Tao → Koh Phangan | 9:30 AM | 10:30 AM |
| Lomprayah | Koh Tao → Koh Phangan | 3:30 PM | 4:45 PM |
Koh Tao - Koh Phangan Passenger Ferry by Laemsor Lomprayah Ferry
So, what do you think? Even though Koh Tao is a small island, it's packed with amazing experiences! Whether you're into snorkeling, scuba diving, relaxing walks along the beach, enjoying delicious food, or sipping wine by the sea, there's something for everyone. Adventure lovers will also find plenty to enjoy, from rock climbing to exciting water sports like kitesurfing and kneeboarding. No matter your travel style, Koh Tao has activities to keep you entertained throughout your trip. Now it's time to pack your bags, get ready for an unforgettable island escape, and start planning your journey to Koh Tao.
