I went to Thailand (and Laos) for 2 months recently, got back at the end of Jan. Did a reasonable amount of diving in Pattaya and on Phi Phi, a couple of my friends also got there open water on Ko Phan Yang (or however its spelt)
Overall we found it was very difficult to hire gear from LDS's they always wanted you to come out on their boat for the day and pay for the group package - divemaster, lunch, the boat etc.
As for shore dives we didn't come across many, certainly the more spectacular dive sights are out in open water, if you go too thailand there are 2 dives I highly recommend, the first is Hin Muang which is south of Phi-Phi and can be reached from Phi-Phi by speed-boats (the relative expense of the dive is well worth it, the speed boat itself is so much fun it would be worth going on even if you didn't dive, ours in particular had twin 200 horsepower engines) :mouth:
The second is the Hardeep, a Jap freighter sunk by the Allies in WW2 close to Pattaya (which is 2 hours south of Bangkok) it's a great wreck dive that's very open and easy to penetrate, you don't even need a reel really, might as well use one though I suppose to be mr. safety
The dive shops I went through were 'Phi-Phi scuba' on Phi-Phi who were reasonably professional, and Larry's dive in Pattaya who were very good. Best thing about Phi-Phi scuba is they always take a cameraman with your dive group and film everything and you can buy the footage on VHS or VCD for about $US40 I think, not a bad way to capture a dive with heaps of Mantas.. we personally didn't run into any whale sharks
The only trouble with Phi-Phi and Ko Phan Yang was the hire gear, especially the BC's were nasty:holycow: they looked like they were as old as I am but you get that on remote islands I suppose, they did function ok at least. If I could of I would of brought my own BC and regs.
If you have any more questions about it let me know, otherwise enjoy the holiday, especially the cheappppp food!! Phi-Phi's food is awesome.
PS we all stayed clear of Phuket because its so expensive accommodation wise but the diving sounds awesome around there.
Have fun