The hong, or "rooms", of Phang Nga Bay and Krabi are collapsed cave systems open to the sky, filled with jungle flora and fauna, and often accessible only in tough, purpose-designed inflatable canoes through sea-caves at low tide. Local operators have so far gained access to dozens of hongs between Phang Nga and Krabi to the south. The various hongs each tend to have their own distinct character, and it's easy to spend days, even a week, visiting island after island. Limited numbers of people are taken out at a given time; and guides accompany every boat, not just to lead the way and to provide commentary, but also to advise on ways to conserve these precious natural resources. Although there may be a week or two of inclement weather every year, sea canoeing is fun virtually any time of year in Phang Nga Bay. Indeed, it is enjoyable even during the south-west monsoon, which is the rainy season on the Andaman side of Thailand. The islands and hongs often assume an unearthly beauty in the rains and, inside the caves, the stalactites sparkle even more. Still, for those who like their sunshine, December to March is most highly recommended.