As I understand it you can get a ferry - "from Ao Yai the most popular beach on Chang, Ko Chang Bungalows run a mid-size ferry to the Phayam pier at around 0900 returning 1600. Ko Chang's Bungalows' ferry out of Ao Yai to Phayam. Nice 1 hour cruise down the less seen mountainous west coast of Little Chang. Sure beats the go back to Ranong, change ferries, go out to Phayam (4+ hours)" - Is this still up to date?As for Phayam, still trying to choose between Aow Khao or Aow Yai beach?
Update: yes there is...
"There is a boat between Phayam and little Ko Chang. Actually two of them. The main Phayam ferry can drop you off at the south end of little Chang. And one of the bungalows on the main beach little Chang runs a boat between the two islands - in high season at least. I've used both of these to change islands.Can't remember actual names - got details on my lttle Chang and Phayam pages - tezza
"there have long been direct boats organised by the bungalows from Ao Yai to Ko Payam . Its just there may be times when they are not running , or there is not enough people at the time to share the boat . In that case going to Sapah Hin is a back up option. By the way Saphan Hin is very pretty , beautiful views of the coast and very secluded although the beach is only rough coarse sand , very inexpensive to stay there."