OnTheSpot
Contributor
There are still not so many boats heading to Hin Daeng and Hin Muang, but it has been on the rise over the last few years. The dive sites are great, but you can be unlucky and be there at the same time as a couple of liveaboards plus day trip boats from Lanta and Phi Phi. But if you're in Thailand in April it's not so busy, and yet is the best time of year to dive. The Mermaid II, Colona 6, Pawara and Parinee liveaboards will dive there weekly, all departing from Phuket.
A hat full of options for the Similan islands/Richelieu Rock, departing from Phuket or Khao Lak. Over all Phuket is the best base, but I'd stay flexible. If you want to get some dives at Phi Phi, do it from Phi Phi rather than Phuket. If you want day trips to Similan do it from Khao Lak.
Useful links (even if I do say so myself):
Liveaboards
Thailand Dive Sites
A hat full of options for the Similan islands/Richelieu Rock, departing from Phuket or Khao Lak. Over all Phuket is the best base, but I'd stay flexible. If you want to get some dives at Phi Phi, do it from Phi Phi rather than Phuket. If you want day trips to Similan do it from Khao Lak.
Useful links (even if I do say so myself):
Liveaboards
Thailand Dive Sites