Giant trevally are the apex predators of the Indo-Pacific reef system and the Andaman Sea holds some of the largest, most accessible populations available to sport anglers anywhere in the region. This seven-day itinerary concentrates on nothing else: five nights on a liveaboard working the Similan and Surin archipelagos on heavy popping and jigging tackle, followed by two days of inshore limestone wall fishing in Phang Nga Bay. It is the most focused GT itinerary available in Thailand, and the Andaman delivers.
Physical preparation matters for this trip. GT popping with PE6–8 rods for six hours per day is demanding — conditioning your casting arm, shoulder, and core in the weeks before departure noticeably improves both catch rate and enjoyment. A weak shoulder on Day 4 means missed strikes.
Why the Andaman for GT?
Thailand's Andaman coast offers GT fishing that competes with the world's best locations — Seychelles, Christmas Island, PNG — and does so at a fraction of the cost, with a first-rate liveaboard infrastructure and guides who understand the species at a practical level. The Similan and Surin island groups sit within a national marine park whose protected status has allowed GT populations to recover to genuinely impressive levels. The fish are large, numerous, and in water that is accessible without a five-day ocean crossing.
The Andaman GT population is one of the Indo-Pacific's genuine success stories. Protected reefs produce protected fish — and these fish are very large.
Compare the Andaman with other global GT destinations in our Thai vs Pacific GT Fishing article. The cost and accessibility argument for Thailand is compelling.
Day 1: Tap Lamu Departure
Tap Lamu is Thailand's primary liveaboard departure point, positioned about 30 km south of central Khao Lak. The pier serves the full fleet of Similan and Surin liveaboards and has been doing so since the 1990s. Arrive at the boat with a minimum of three hours before departure — tackle rigging on a moving vessel in the dark is miserable.
The overnight steam north to the Similans takes approximately six hours. Most operators depart in the late afternoon or early evening to arrive at the islands pre-dawn, maximising the first light fishing window. Use the crossing time wisely: sleep if you can, rig your terminal tackle, and charge camera batteries. Squid jigging from the stern is productive on the crossing and the crew typically fries calamari for the first evening's appetiser.
See our Liveaboard Operators Thailand guide for the recommended vessels operating this route.
Days 2–3: The Similan Islands
The Similan archipelago comprises nine granitic islands rising from a sea floor that drops to 30 metres between island groups and hundreds of metres in the open channel sections. The underwater topography — pinnacles, boulders, canyon walls — creates current acceleration and prey concentration that drives GT feeding. Understanding the structure is as important as executing the cast.
Pinnacle Popping
Similan GT fishing at its most concentrated happens on the submerged pinnacles north of Island 9. These rocks top out at 2–5 metres below the surface on a low tide and attract baitfish in volumes that in turn attract GT in feeding frenzies visible from 100 metres away. The technique is straightforward: position the boat up-current, cast large cup-face poppers across the pinnacle face, and retrieve as fast as you can manage. GT on pinnacles are competitive feeders — speed triggers the strike.
GT strikes on poppers are violent and sudden. Keep your rod at about 45 degrees during the retrieve and be prepared to let the bow load before you wind — attempting to strike by raising the rod typically results in the lure being pulled out of the fish's mouth. Wind down and lift.
The afternoon jigging on the pinnacle faces produces a different class of GT — fish holding at depth on the down-current edges. Work 200–300 g jigs through the current shadow with a high-speed retrieve. Strikes come on the fall or during the initial acceleration.
Southwest Bank
The southwestern Similan bank is lower relief structure — broad reef flats that GT patrol on the tide. Popping along the reef edge at first light produces in conditions where there is a visible tidal push. Slower retrieves work better here than on the pinnacles; the fish are ambushing rather than competing.
Day 4: Deep Canyons
The canyon system between the Similan and Surin groups is the dogtooth tuna zone. These fish grow to 100 kg+ and fight without any of the spectacular surface acrobatics of GT — they simply run deep, hard, and long. A hooked dogtooth will strip 150 metres of line on its first run and keep pulling. The only technique is maximum drag, bent rod, and the willingness to pump a heavy jig reel for 30 minutes.
Wahoo appear on the open water crossing — trolling produces fish in the 20–40 kg range and they are fast, clean fighters on light trolling gear. The captain will identify feeding birds and active surface schools; be ready to drop rods and cast when the boat pulls up to a school.
A dogtooth tuna fight is not spectacular. It is simply relentless — and that turns out to be more demanding than spectacular.
See the Andaman Deep Canyons article for a full breakdown of the canyon system, jig selection, and realistic expectations for this section.
Days 5–6: The Surin Archipelago
The Surin Islands offer the most diverse GT fishing on the liveaboard circuit. The outer bommies — isolated coral heads in 5–15 metres of water — attract concentrations of GT that hold resident populations and supplement them with transient fish moving between the islands. These fish are more aggressive and less educated than the Similan fish, which see slightly more pressure.
The key difference at Surin is the visual nature of the fishing. On a calm morning with good light, you can see the GT before you cast. Dark shapes moving on the edge of a bommie at dawn, the occasional flash of silver as a fish turns, the surface eruption as a school of baitfish is driven up — these are sight-fishing conditions that allow the guide to direct your cast to specific fish.
By Day 5 most anglers have a feel for how GT behave during feeding windows. The strike rate typically improves over the liveaboard progression — technique calibrates, lure selection narrows, and the reads on fish behaviour improve with accumulated observation. This is when the trip pays its best dividends.
Inshore Bonus Species
Surin's inshore water holds bluefin trevally in numbers, and on lighter spinning tackle (PE2–3 with 60–80g lures) they are excellent sport. Coral trout, various snapper species, and the occasional barramundi-like GT relative add variety to the afternoon sessions when the peak popping windows have passed.
For the full species breakdown see our GT Popping Andaman guide and the Similan Islands Fishing and Liveaboard Fishing Thailand profiles.
Day 7: Phang Nga Limestone Walls
The contrast between offshore Andaman and inshore Phang Nga is total. After five days on open water among granitic islands, the limestone karst towers of Phang Nga Bay are a different country. The water is greenish rather than blue, the towers rise hundreds of metres above sea level, and the GT here behave differently — less competition, more ambush, and a visual environment that makes every session feel like it is happening inside a film set.
The technique for limestone wall GT is precise casting rather than maximum distance. The fish hold close to the rock face and strike from the shadow. Position the boat parallel to the wall, cast as close to the limestone as possible (within 50 cm is ideal), and work the lure away from the wall on a fast retrieve. Takes are often explosive and immediate — the fish does not follow the lure from a distance, it hits it as it leaves the rock.
Mono-wrap leaders are recommended for the limestone wall fishing. The rock surface will contact your leader during the fight if the fish runs toward the wall — abrasion-resistant leaders of 200 lb plus reduce cut-offs significantly.
The afternoon's second limestone wall session covers different sections of the bay. Phang Nga Bay is vast and the limestone formations extend for kilometres — guides know which walls are most productive at each stage of the tide and will route the day accordingly.
This final day is the most visually dramatic fishing of the week. After the open Andaman, the enclosed limestone channel fishing is intimate by comparison, and the GT here — even if smaller on average than the offshore fish — fight in confined water that makes them feel larger.
Tackle Specifications
Popping Setup
- Rod: 9'0"–9'6", PE6–8, solid tip graphite or carbon composite
- Reel: Large lever-drag overhead (Shimano Stella 20000HG or Daiwa Saltiga 20H equivalent), or spinning reel with 150 lb drag minimum
- Main line: PE6–8 braid (80–100 lb), 300 m minimum
- Leader: 150–200 lb fluorocarbon, 2–3 m, connected via PR knot
- Lures: Cup-face poppers 160–250 g; pencil poppers 120–200 g; stickbaits 120–200 g
Jigging Setup
- Rod: 6'0"–6'6", PE3–4, high-speed jigging action
- Reel: High-speed lever-drag overhead (7:1+ retrieve ratio), PE4 braid
- Jigs: Knife and centre-balance metal jigs 200–400 g, bright colours and UV patterns
- Leader: 100 lb fluorocarbon, 1.5 m
The GT Popping Tackle Guide covers every component in detail. All tackle is available for rent from quality liveaboard operators — confirm specifications and availability when booking.
Realistic Expectations
GT fishing on the Andaman is not guaranteed production. On a five-night liveaboard with good conditions you should expect multiple encounters and a reasonable hook-up rate. A session on the Surin outer bommies in November or December can produce 10–20 GT strikes per day per angler with good technique. A rough-weather week with churned-up conditions can produce far less. November through February represents the most reliable weather window.
The limestone wall GT fishing on Day 7 tends to be more consistent in terms of encounter rate — the fish are resident rather than transient, conditions are calmer inshore, and the guide's local knowledge is extremely precise. Many anglers find Day 7 produces their most memorable captures of the week.
Seven days chasing GT in the Andaman is not a balanced fishing holiday — it is a specific pursuit of a specific fish that happens to be excellent at resisting capture. That is why you are here.
