The Gulf of Thailand is a productive fishing ground. Dozens of sport fish species inhabit the waters around Koh Samui, and the deeper water to the north — towards Koh Tao and Chumphon Pinnacle — holds serious trophy specimens. Sea fishing from Samui works for beginners who simply want to get out on the water and catch something, and for experienced sport anglers hunting big game.

Key Species

Barracuda — one of the most common fish in Samui's coastal waters. An aggressive predator that takes lures readily and fights hard. Often caught trolling along reef edges.

Yellowfin tuna — the premier offshore trophy species in this region. Predominantly found in deeper water to the north and east of Samui. Requires heavy gear (PE 6–10 braided line, high-capacity reels) and experience in fighting powerful fish.

Mahi-mahi (dorado) — a fast-moving open-water species identifiable by its brilliant gold-green colouration. An excellent fighter and popular for catch-and-release.

Spanish mackerel — common near the surface, takes spinning lures well, and is an approachable target for beginners. Also good eating.

Grouper (epinephelus) — a reef bottom-dweller. Caught on live bait and jigs at 20–50 m depth. Frequently found around Koh Matsum and other small islands south of Samui.

Wahoo — one of the ocean's fastest predators and a highly prized trophy. Rare but possible on deep offshore trolling runs.

Fishing Formats

Deep-sea / offshore fishing — targeting water 30–80 m deep. Target species: tuna, mahi-mahi, wahoo. Heavy tackle required. Typical format: an 8-hour trip with 4–6 rods, captain with sonar and sea surface temperature charts.

Reef fishing — working depths of 10–30 m near coral structures. More relaxed pace, suitable for families and beginners. Varied and reliable catch.

Half-day trips — 4–5 hours, ideal for guests who want to combine fishing with other activities the same day. Generally stay within sight of the island.

Best Time to Fish

November through April — main season: calm seas, good visibility, tuna active. December through March are peak months for big game at the Chumphon Pinnacle depths. May through October — fishing is possible in sheltered inshore waters, but offshore trips are limited by unsettled weather.

Practical Tips

  • Confirm what is included: tackle, bait, ice for your catch, fish cleaning and packing.
  • Take seasickness medication if you are sensitive to swell — offshore trips can get bumpy.
  • Ask the captain about catch-and-release policy for large trophy species (marlin, sailfish, wahoo); many responsible operators release after a photo.
  • UV clothing and a hat are essential — several hours on open water under tropical sun.
  • Water and snacks are usually on board, but bring extras.