Ko Samui

Ang Thong National Marine Park — scuba and snorkeling within striking distance

Ko Pha Ngan — home of the infamous Full Moon Party in Haad Rin, but there are also near-untouched landscapes -- and detox centres.

Ko Tao — among the best places in Thailand to learn to dive, actually the biggest dive school on the planet. Apart from diving sailing is an option to go to the Ang Thong Marine National Park.

Surat Thani — the mainland's closest big city

Pattaya, Phuket and Chiang Mai — a short hop away on Bangkok Airways