The area bounded by Phuket, Phang Nga and Krabi provinces forms Phang Nga Bay. There are over 100 islands, and the geology varies from low gently sloping mountains to the steep karst outcrops for which the bay is most famous.
At the south end of Phuket is a large protected bay, Ao Chalong, which is the usual port of entry into this region and where the main port control centre is located.
Koh Hong Group
The best anchorage in this group of islands lies between Koh Hong and the shallow water to the west of Koh Na Khae. Suitable for both seasons, this very picturesque anchorage has good holding in approximately 12 metres on a muddy bottom, and gives easy access to Koh Hong should you want to explore by dinghy.
Please remember to take a set of paddles in your dinghy so you don't have to run your outboard engine whilst inside the hong.
Care ought to be taken, if heading north from this location, to keep well clear of the shallow bank to the west of Koh Na Khae. The passage between Koh Yai and Koh Na Khae is not recommended for any but shoal draft vessels.
Yachts proceeding east from this group should pass north around Koh Na Khae or south of Koh Yai.
Another anchorage is to be found just south of Koh Hong in 4 - 5 metres on a muddy bottom directly outside the small cave that opens into the lagoon.
Both these anchorages are very busy with day trips and sea canoe tours coming and going during the day.
If swimming in these channels beware of strong currents, particularly during spring tides.
North Phang Nga Bay
The sheer-sided sea mountains that rise vertically out of Phang Nga Bay form some of Thailand's most spectacular scenery. Images of Phang Nga have travelled the world and shaped many people's perception of southern Thailand, and the boating experiences to be had here.
As a result the cruising yachtsman may encounter many tour boats with sea canoes during the middle hours of the day but tranquility does return by late afternoon.
While the bay itself is not so large, the number of islands, inlets and mangrove channels to be explored ensure that no matter how long a yachtsman spends here, new experiences will always be nearby.
Most of the islands are uninhabited, offering secluded anchorages under soaring cliffs fringed with jungle, as well as fascinating dinghy expeditions to hidden beaches, caves and creeks not shown on charts or maps.
Three rivers run into the head of the bay so the water is silty, though otherwise clean, forming a milky green backdrop to the striking scenery.
Since a large part of the area north of Koh Yao is shallow (less than 10 metres), it is possible to anchor virtually anywhere in north Phang Nga Bay.
Some of the area is National Park and rangers patrol around the islands. The entry fee is 200 Baht per boat and 200 Baht per day per person on board, which is collected on the spot.