Hotel construction is prohibited on the Small Island, so you can live on the Big Island, or buy a special package tour providing the night in a tent on the beach. Find hotels in Maya Bay
How to get there 
Fly to Phuket airport (HKT)
or to Krabi airport (KBV)
. Next take a ferry (1.5 hours, 400 bahts).
If you plan a combined tour in South-East Asia, it is possible fly to Krabi, next take a ferry to the island of Phi Phi, next take a ferry to Phuket island and next fly where you need. Find flights to Maya Bay
When to go 
From December to April is a period of sunny weather with almost no rains. The rest of time the sky is mainly covered with dark clouds.
Water temperature, C
Wind speed, meter/sec