Thanks for your report.

Did you notice any of the beaches facing away from Pattaya not illuminated at night? I'm looking for a place without artificial light to swim in fluorescent plankton at night. It seems to be everywhere in the Bay of Thailand, even Jomtien, however barely noticeable there for all the light on the beach.

I have been to Koh Larn twice and other than swimming in plankton*, I have little reason to go again. However, it is very popular with local and foreign tourists for what I call "the Notre Dame effect" (because I noticed this when I was working near Paris and visiting Paris frequently). There are hundreds of islands that are comparable to Koh Larn, even better because fewer tourist, but they are not as quickly accessible from Pattaya.

*or the wooden boardwalk over rocks on the beach, and it has been many years since my last visit so a return would be interesting.