The cast net — known in Thai as haek — is one of the oldest and most effective methods of collecting live baitfish anywhere in the tropics. A well-thrown net over a school of mullet or herring produces in thirty seconds the baitfish that might take an hour to collect by hook and line. For serious bait fishing in Thailand, the cast net is not optional equipment — it is the difference between arriving at the venue with a bucket of vigorous, perfectly-sized live bait and relying on whatever the lakeside stall has available.
Understanding Cast Nets
A cast net is a circular weighted net attached to a central retrieval line. When thrown correctly, it spreads into a full circle in the air, sinks rapidly, and the weighted perimeter closes beneath the fish as the net is retrieved. The construction variables — mesh size, net diameter, lead weight, and material — determine which species the net catches effectively and in which environments it can be used.
Net Diameter
Cast nets for bait collection in Thailand typically range from 1.8 to 3 metres radius (the throw distance from the centre to the edge). Larger nets are more effective in open water where mullet are spread, but they require significant upper body strength and technique to throw correctly. A 2.4 metre net is a practical maximum for most anglers working from a boat or wading a tidal flat. Beginners should start with a 1.8 metre net until the throwing technique is developed.
Mesh Size for Target Species
Mullet (15–30 cm): 18 to 22 mm stretched mesh. This size retains mullet of usable bait size while allowing undersized juveniles to escape through the mesh before the net closes. A smaller mesh creates excessive water resistance and slows the net's sink rate, allowing fish to escape beneath the edge.
Small herrings and sardines (8–15 cm): 10 to 14 mm stretched mesh. Finer mesh is needed to prevent these smaller, more slender fish from escaping. The trade-off is reduced sink speed; compensate by increasing the lead weight at the perimeter.
Tilapia (8–15 cm) in still or slow-moving water: 12 to 16 mm mesh. Tilapia have broader bodies than herrings and a slightly larger mesh is workable. In still-water environments like pay-lake margins and canal systems, a lighter lead weight is adequate.
Small catfish, perch, and mixed baitfish: 14 to 18 mm mesh covers most of the mixed small-fish scenarios encountered in Thai freshwater systems.
Material: Monofilament versus Nylon Braided
Monofilament cast nets are lighter, less visible in clear water, and easier to handle when wet. They are appropriate for clear-water collection — around estuaries, beach areas, and the clearer canal systems of central Thailand. The limitation is durability: monofilament nets snagged on oyster shell, coral rubble, or submerged timber tear more readily than braided nets.
Braided nylon nets are heavier, more visible in water, and require more effort to throw to full diameter. They are significantly more durable and are the correct choice for murky water, rocky estuaries, and mangrove environments where snags are frequent.
Net Care
Rinse your cast net in fresh water after every saltwater session and hang it to dry fully before storage. Salt crystals in a stored net corrode the lead weights and weaken the mesh filaments. A net stored wet develops mildew that degrades the nylon within a season.
The Throwing Technique
Learning to throw a cast net to full diameter is a skill that requires practice. Most visiting anglers who have never used one will not achieve a full circular throw on the first attempt — this is normal and does not mean the method is unavailable to them.
Preparation
Lay the net on a flat surface and identify the retrieval line (main line), the horn or yoke at the centre, and the weighted perimeter. Remove any tangles. In Thailand, cast nets are sold coiled and packed — always inspect for tangles before attempting a throw, as a tangled net cannot open correctly.
Coil the retrieval line loosely and hold it in your non-dominant hand. With your dominant hand, gather approximately one-third of the net from the perimeter and drape it over your throwing arm between the elbow and wrist.
The Throw
Stand facing the water at an angle of roughly 45 degrees to your target school. The motion for a right-handed thrower is:
- Hold the horn of the net in the left hand, retrieval line coiled loosely in the left palm.
- Drape the gathered perimeter section over the right arm.
- Twist the upper body to the left, loading the throw.
- Release in a smooth horizontal sweeping motion across the body, releasing the perimeter section from the arm at the apex of the throw.
- The net should open into a full circle in the air and descend flat onto the water.
The entire motion takes approximately one second. The common error is releasing the net too early, which causes it to bunch in the centre rather than opening fully. A net that lands in a bundle catches nothing.
Reading the Water Before Throwing
In Thai estuaries and tidal areas, fish schools are often visible as surface dimpling, sudden flashes of silver, or birds diving. Circular schools of mullet feeding at the surface are the ideal target — wait until the school is within comfortable range (20 to 25 metres for a practiced thrower, 10 to 15 metres for a beginner) and lead the school slightly with the throw to allow the net to open fully before the fish reach its centre.
Where to Cast-Net in Thailand
Estuaries and River Mouths
The river mouths of the Chao Phraya near Samut Prakan, the Bang Pakong River at Chachoengsao, and the Tapi River at Surat Thani all produce mullet in large numbers, particularly in the tidal rips between high and low water. Mullet move upstream with the tide and drop back with the ebb — cast-netting on a falling tide where the river narrows concentrates fish and produces better catches.
On the Andaman side, the river mouths near Ranong, the Trang River estuary, and the channels around Pak Bara in Satun are productive for mullet and small herrings that form the core live bait supply for charter fishing in those areas.
Piers and Jetty Structures
Pier lights at night attract herrings, sardines, and small anchovies in enormous numbers in both the Gulf and the Andaman. The concrete pier at Rawai in Phuket, the Chalong pier, and the jetties near Koh Samui's Na Thon ferry terminal all hold dense baitfish concentrations around the light columns from dusk onward. A small cast net with fine mesh thrown into the lit zone produces baitfish in large quantities within minutes.
Beach and Surf Zones
Schools of small herring and sardine are often visible from the beach in the early morning as cormorants and terns work the surface. On the Gulf beaches of Hua Hin, Cha-am, and Chumphon, wading chest-deep with a 1.8 metre net and throwing onto the school as it moves along the shore is a traditional collection method used by local bait gatherers who supply the charter fleets.
Pay-Lake Margins
At freshwater pay lakes, cast-netting in the lake's margins for tilapia is straightforward. Most Thai pay lakes permit bait collection from the water, but confirm with the venue operator before casting — some premium facilities prohibit in-lake collection to protect the stocking density. The canal irrigation systems surrounding Bangkok in the Nong Khaem, Minburi, and Lat Krabang areas are reliable free-access collection sites.
The angler who arrives with thirty vigorous, freshly netted mullet is starting the session with a twenty-minute advantage over the one buying from the stall. Live bait quality at the point of collection determines catch quality at the end of the day.
Legal Status and Regulations
Thailand's Fisheries Act B.E. 2558 (2015) and associated regulations govern cast netting in terms of mesh size, location, and collection purpose. For personal bait collection:
- Cast netting with nets under 4 metres diameter for personal use is generally permitted in public freshwater and tidal waterways.
- Any collection in national park waters, wildlife sanctuaries, or designated no-fishing zones is prohibited regardless of method.
- Commercial collection requires a permit. Selling the fish you collect without a commercial licence is illegal.
- Certain net types with mesh smaller than 1 cm are prohibited regardless of purpose, to protect juvenile fish populations.
Practically, visiting anglers cast-netting in public estuaries and canals for personal bait use are rarely challenged by authorities, but violations in protected areas are enforced. The signage at national park entry points is explicit on the fishing prohibition, and the boundaries of marine national parks in both the Andaman and Gulf are well-marked on navigation charts.
Target Species Summary
| Species | Mesh Size | Best Location | Best Time | |---|---|---|---| | Mullet (15–30 cm) | 18–22 mm | Estuaries, tidal flats | Dawn, dusk | | Small herring | 10–14 mm | Piers, jetty lights | Night, early morning | | Tilapia (8–15 cm) | 12–16 mm | Canals, lake margins | Any daylight | | Small sardine | 10–14 mm | Beach surf zone | Early morning | | Mixed baitfish | 14–18 mm | River mouths | Falling tide |
Maintaining your collected baitfish in good condition from net to water is covered in the bait aerator systems guide, which covers the hardware needed to keep live collections viable through a full session in Thai heat.
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