That was a quick reply from work yesterday but it's the only freshwater fishing I know of in the island.
I've never fished Samui but I did visit Koh Tao a few years back. Most beaches are broken coral and I had a few small fish from several unidentified Lucjanid species from the shore- I only had a very light spinning rod with me. There was no real boat fishing action though because the seas around Koh Tao are a marine park. I don't think that that's the case with Samui but it might be wise to d a google search.
If you're going to Samui, you will presumably be on the mainland at some point so if you're near a major resort town, just drop it's name and "fishing park" into a search engine and see what comes up. I did just that a couple of weeks back and spent a very pleasant couple of days fishing at Hua Hin Fishing Lodge on an all inclusive package that included hotel pickup, rental of two rods, bait, a guide to do my unhooking and photography, a slap up Thai lunch, hot and cold non-alcoholic drinks and a return trip back to the hotel. Total cost for the day was 2000 baht (3000 Rupees) which isn't bad.
Last edited by Ken L on Sun Dec 06, 2009 1:08 pm, edited 1 time in total.