Since there hasn't been one for a few years. I don't understand why more foreigners don't go there. Thais too actually. When you think how many go to koh larn and samet. And this is closer.
From bangkok get the bus from ekkamai to sri racha. From pattaya get a minivan to sriracha. From sri racha get a tuk tuk to the pier, 60 baht, or walk. Ferry is 50 baht, 60 baht if last ferry.
The island is really pretty. The beaches are very small, but they're swimable and do the job. There are a lot of quiet little tracks all over the place and exploring on a motorbike is a good option. Bicycles can be rented near Charlie's bungalows, in a side street about 100m before. 120 baht for a day. Hilly island, motorbike recommended.
Accommodation is really expensive relative to other Thai islands. I'm really not sure why.
Its so easily done as a daytrip from bkk so you don't have to stay necessarily. Boats are convenient for daytrippers with the last boat back to sri racha leaving 7pm.
From sri racha back to bkk you can get a minivan outside Robinson's, or the bus from the bus station next to tukcom.
A really good alternative to the usual daytrips like kanchanaburi and khao yai and Ayutthaya.