Sonar / Depth Reading

The art of reading nature.
Calm & adrenaline.

Fishing is practice in reading nature: current, depth, and timing. That is where the calm comes from — and the adrenaline of the first strike.

Learn Techniques Find a Setup

Navigation

Want to go fishing? Start here.

Five steps that always apply, whatever fish you are after. No drawn-out theory, no jargon.

01
Learn the Techniques
Study every technique from bottom fishing to trolling, complete with its gear specifications.
02
Find a Setup
Assemble a complete set: rod, reel, line, leader, hooks, and bait.
03
Find a Fishing Spot
Know the habitat: deep offshore, reefs & surf, estuaries, or lakes and rivers.
04
Pick Your Target Fish
Learn the habits and weaknesses of your quarry before you cast.
05
Go Fishing
The gear is ready, the target is set. Time to head out.

BRG000°DEPTH300m

Giant Trevally (GT), Caranx ignobilis
Yellowfin Tuna, Thunnus albacares
Monster Grouper (Kerapu), Epinephelinae
Barramundi, Lates calcarifer
Giant Snakehead (Toman), Channa micropeltes
Mahi-Mahi (Dorado), Coryphaena hippurus
Red Snapper (Kakap Merah), Lutjanus campechanus
Hampala (Jungle Perch), Hampala macrolepidota

Active Sonar

What cannot be seen
is not assumed to exist.

Fishing works on echoes. Every signal that comes back to the transducer carries news of what is below — position, size, distance. At work the pattern is similar: what cannot be seen still has to be measured.

Sonar works because it does not guess. It transmits, waits, then compares what returns against what was expected. Patience is not boredom here; it is the method.

Start Reading Nature

Knowledge Base

Learn the techniques.

Understand the character of the water, then pick the technique that best fits the challenge of the day.

01
Dasaran (Bottom)
The purest technique, and still the most effective. The bait is left to sink with a weight until it touches the bottom, working with the habit of demersal fish that feed around reefs, drop-offs, and sand flats. The key is two things: reading the current below and feeling the bite through the rod tip.
View specifications →
02
Casting
The art of working artificial lures. The lure is cast to a strategic point — a gap in the mangrove roots, rocks, or a coral crevice — then retrieved with a jerking or twitching action. The goal is one thing: make the lure look like a wounded fish, so the predator's instinct fires.
View specifications →
03
Jigging
A physical fight with pelagic predators in deep water. The metal jig is dropped straight to the bottom, then worked upward in rhythm with a purpose-built rod. That rising and falling motion imitates a squid or small fish panicking toward the surface.
View specifications →
04
Popping
Tropical saltwater adrenaline in its purest form. The popper is cast over strong-current reef, then swept hard so its cupped mouth throws water. The explosion and the "Pop!" are what bring the GT up to hit the lure in front of your eyes.
View specifications →
05
Trolling
The method for covering wide water. The lure is let out far behind the boat, the rod goes in the holder, and the boat runs steady at 5-9 knots. When the reel clicker screams long, a fast predator has taken it.
View specifications →
06
Pasiran (Surf)
Saltwater fishing from a sandy shore, no boat. A heavy bait is thrown as far as possible with a pendulum cast, out to the trough off the beach where fish feed.
View specifications →
07
Fly Fishing
The most technical and most elegant discipline. Unlike ordinary fishing, here the weight of the fly line carries the light fly — fur and imitation insects — through the air in a loop.
View specifications →
08
Negek (Pole)
A grounded traditional approach with a sensitivity that is hard to match. No reel: the line is tied straight to the tip of a long rod with no guides, and the fight is one on one, relying on the flex of the blank.
View specifications →

Architecture

Fishing setup builder.

Pick a technique below, then read the full specification of every component: rod, reel, line, leader, hooks, down to the bait.

Rod
Reel
Line
Leader
Hooks
Lure

Dasaran (Bottom)Casting Jigging Popping Trolling Pasiran (Surf)Fly Fishing Negek (Pole)

Dasaran (Bottom)

The purest technique, and still the most effective. The bait is left to sink with a weight until it touches the bottom, working with the habit of demersal fish that feed around reefs, drop-offs, and sand flats. The key is two things: reading the current below and feeling the bite through the rod tip.

Bottom Fishing Gear

Rod: 1.8m - 2.1m (Medium-Heavy), Solid Carbon Tip for high sensitivity.
Reel: Spinning 4000 - 6000 or Overhead (OH) with a strong drag.
PE Line: PE 3 - PE 5 (Multi-colour to monitor depth).
Leader: Fluorocarbon 40lbs - 60lbs (abrasion resistant against coral).
Hooks: Circle Hook / Baitholder size 1/0 - 5/0 (paternoster or tandem rig).
Accessories: Sinkers (J2-J5), stainless steel swivels.
Bait: Sliced mackerel, whole squid, live prawn, or sliced fillet.

Target & Habitat

Most effective on coral reefs, FADs, offshore drop-offs, and deep piers.

Target Fish

Grouper
Red Snapper
Yellowtail Scad
Emperor

Casting

The art of working artificial lures. The lure is cast to a strategic point — a gap in the mangrove roots, rocks, or a coral crevice — then retrieved with a jerking or twitching action. The goal is one thing: make the lure look like a wounded fish, so the predator's instinct fires.

Casting Gear

Rod: 1.8m - 2.1m, Medium-Light to Medium action (Fast Taper), light enough to cast hundreds of times.
Reel: Baitcasting (BC) 7.1:1 ratio or faster, or Spinning 2000 - 3000.
PE Line: PE 1 - PE 2 (thin so it does not fight the wind on long casts).
Leader: Fluorocarbon 20lbs - 30lbs (1 to 1.5 metres long).
Hooks: Treble Hook 3X/4X strong, size #4 to #8, or Single Inline hooks.
Lures: Minnow (sinking/floating), Pencil, Stickbait, Soft Lure (Froggy), Crankbait.
Accessories: Lure snaps (so the lure action stays fluid).

Target & Habitat

Swamps, fast river banks, mangrove forests, coastal rocks (rock fishing).

Target Fish

Barramundi
Snakehead (Toman)
Hampala
Black Bass

Jigging

A physical fight with pelagic predators in deep water. The metal jig is dropped straight to the bottom, then worked upward in rhythm with a purpose-built rod. That rising and falling motion imitates a squid or small fish panicking toward the surface.

Jigging Gear

Rod: Very short and stiff (1.5m - 1.8m), PE 3-6 for Speed Jig, PE 1-3 for Slow Pitch Jigging.
Reel: Deep-water Overhead (OH), or Spinning 6000 - 10000 with a strong drag system (Max Drag 15kg+).
PE Line: PE 3 - PE 6 (Multi-colour X8). You must know the depth to stop the jig in front of the school.
Leader: Fluorocarbon 50lbs - 80lbs (very long, at least 4 to 8 metres).
Hooks: Assist Hook size 3/0 - 7/0 on unbreakable kevlar thread with shiny pearl dressing.
Lures: Metal Jigs from 80 grams (Light) to 500+ grams (Heavy). Asymmetric or leaf shape.
Accessories: Heavy split rings, stainless solid rings, a Gimbal fighting belt to brace the rod.

Target & Habitat

Open ocean (Offshore), deep water from 50 metres to 300+ metres down. Around oil rigs or undersea canyons.

Target Fish

Amberjack
Dogtooth Tuna
Ruby Snapper
Escolar

Popping

Tropical saltwater adrenaline in its purest form. The popper is cast over strong-current reef, then swept hard so its cupped mouth throws water. The explosion and the "Pop!" are what bring the GT up to hit the lure in front of your eyes.

Popping Gear

Rod: Extremely stiff (Extra Heavy), 2.2m - 2.6m long. PE 6 to PE 10 rating (casts 200g loads).
Reel: Monster-class saltwater Spinning (Size 10000 - 18000+), Max Drag 20kg to 30kg.
PE Line: PE 6 - PE 10 (super-strong 8-braid).
Leader: Popping-grade Nylon Monofilament 100lbs - 170lbs (absorbs shock better than fluorocarbon). 2-3 metres long.
Hooks: Monster Treble Hooks (Size 5/0 - 7/0) in 5X to 6X Strong wire.
Lures: Wood/resin Poppers 100g - 200g (big-cup Chuggers or sub-surface Stickbaits).
Accessories: Split rings 250lbs+, cut-resistant Casting gloves, shallow-water Gimbal belt.

Target & Habitat

Shallow atolls in open ocean, converging island currents, and breaking surf.

Target Fish

Giant Trevally (GT)
Yellowfin Tuna
Mahi-Mahi

Trolling

The method for covering wide water. The lure is let out far behind the boat, the rod goes in the holder, and the boat runs steady at 5-9 knots. When the reel clicker screams long, a fast predator has taken it.

Trolling Gear

Rod: Very thick and stiff (Stand-up rod), often with Roller Guides (rollers in the line guides so they do not heat up). 30lbs - 80lbs class.
Reel: Massive gold/silver Trolling Overheads (30W, 50W, up to 80W) with enormous line capacity.
Line: Thick Monofilament (50lbs - 130lbs) for its stretch against an 80km/h marlin run. Or heavy PE + mono top shot.
Leader: Wire leader for toothy fish like mackerel, or Fluorocarbon >150lbs for marlin.
Hooks: Giant single hooks (Big Game Hook) in stainless steel, size 8/0 - 12/0.
Lures: Konahead (resin head with octopus skirt), Deep Diver Minnow (long lip for 5-10m dives).

Target & Habitat

The endless open ocean (Blue water offshore), the migratory routes of the world's pelagics.

Target Fish

Marlin & Sailfish
Wahoo
Spanish Mackerel
Tuna

Pasiran (Surf)

Saltwater fishing from a sandy shore, no boat. A heavy bait is thrown as far as possible with a pendulum cast, out to the trough off the beach where fish feed.

Surf Fishing Gear

Rod: Very long for distance. Telescopic / 3-piece 3.6m to 4.5m (Surf casting rod).
Reel: Surf-specific Spinning 6000 - 10000 with a wide spool (long cast spool).
Line: Medium Monofilament (0.30mm - 0.40mm) so it does not stiffen in the wind, or PE 2-3.
Leader: Shock leader (thick Monofilament 40lbs - 60lbs, 5 metres long) to absorb the cast's force.
Hooks: Long shank hooks, size #1 to 2/0, to hold the bait securely.
Bait / Accessories: Wire-armoured sinkers (so they dig into the sand instead of washing out). Bait: sand crabs, sea worms, sliced squid.

Target & Habitat

Sandy ocean beaches, river-mouth surf zones with heavy swell.

Target Fish

Stingray
Shore Giant Trevally
Queenfish
Small Reef Sharks

Fly Fishing

The most technical and most elegant discipline. Unlike ordinary fishing, here the weight of the fly line carries the light fly — fur and imitation insects — through the air in a loop.

Fly Fishing Gear

Rod: Weight-rated Fly Rod (not Lbs/PE). E.g. 5WT (freshwater), 8-10WT (saltwater / big fish). Flexible from tip to butt.
Reel: Fly Reel (Arbor). Mostly just stores the line; it does not winch the load (pulled in by hand).
Line: Fly Line (very thick, PVC coated; Floating or Sinking types) + Backing Line as reserve for long runs.
Leader: Tapered Leader (thins toward the tip) joined to a Tippet, size 0X to 6X (very fine, translucent).
Hooks & Bait: Hand-tied Flies from imitation animal fur. Dry Fly (floats) or Nymph/Streamer (sinks).

Target & Habitat

Clear rocky streams, mountain headwaters, quiet lake margins, and some fine-sand shallow salt flats.

Target Fish

Trout
Hampala
Tarpon
Bonefish

Negek (Pole)

A grounded traditional approach with a sensitivity that is hard to match. No reel: the line is tied straight to the tip of a long rod with no guides, and the fight is one on one, relying on the flex of the blank.

Negek Gear

Rod: Tegek pole rod. Full Carbon so it stays light for hours. Lengths vary from 3m, 4.5m, up to 7m.
Reel: No reel. The line is tied to the tip cord along the rod.
Line: Very fine translucent Monofilament (0.15mm - 0.25mm) so wary fish cannot detect it.
Leader: The rig is a sensitive needle float (styrofoam), stoppers, and folded lead shot for balance.
Hooks & Bait: Very small single hooks (size #1 to #5) or double Garong hooks. Favourite baits: fine fresh moss, worms, tiny shrimp, or custom pellets.

Target & Habitat

Calm margins. Abandoned shrimp ponds, steep reservoir dams, lily ponds, concrete harbour jetties.

Target Fish

Tilapia & Milkfish
Rabbitfish
Mullet

Locations

Find a fishing spot.

Every stretch of water has its own character and its own king. Learn the ground, master the technique, then prepare your gear properly.

Deep Offshore

The territory of big pelagic fish. Fishing the open ocean, sea mounts, or around oil rigs and FADs. It demands physical and mental readiness: bad weather, big swell, and fights that can last hours.

Best Techniques: Jigging (Speed & Slow Pitch), heavy Popping, ocean Trolling, Deep Drop Fishing.
Main Targets: Yellowfin Tuna, Marlin, Giant Trevally (GT), Amberjack, Dogtooth Tuna, Mahi-Mahi.
Preparation & Specialist Gear: Heavy tackle (PE 5-10). Bring a gimbal belt to brace the rod against your waist when a fish pulls tens of kilograms. Pack seasickness tablets, casting gloves, non-slip boat shoes, and offshore rain gear. Safety stays the priority.

Reef & Surf

Rocky coastline with reef and surf breaking on the shore. Hunting ground for ambush predators, which use the foam to strike small prey in the gaps between coral.

Best Techniques: Pasiran (Surf Casting) on sand flats, Rock Casting (casting lures from cliffs), shore Light Jigging, Negek.
Main Targets: Shore Giant Trevally (GT), Stingray, small Reef Sharks, Grouper, Snapper, Queenfish.
Preparation & Specialist Gear: Reef shoes (felt spikes) are essential to keep from slipping or stepping on sea urchins. For rock fishing on wave-washed cliffs, a life jacket is mandatory. Use a long surf rod (>3.6 m) to keep the line off the rocks.

Estuary

Where fresh water meets salt, shaped by mangrove forest and tide. This brackish water is rich in nutrients and home to predators that like to ambush from cover.

Best Techniques: Close-range Casting (Topwater, Jerkbait, Minnow), light bottom fishing on live prawn, Fly Fishing.
Main Targets: Barramundi, Mangrove Jack, Estuary Grouper, Tarpon, Black Bass.
Preparation & Specialist Gear: Often needs a small boat or kayak. A thick fluorocarbon leader (40lbs+) is essential, because mangrove roots are covered in oyster shells that can cut the line. Bring insect repellent, and watch for saltwater crocodiles in remote spots.

Lake & River

True freshwater: rocky mountain streams, wide reservoirs, and swamps covered in lilies and weed.

Best Techniques: Casting (Frog lure / Soft lure), Negek (Pole fishing), freshwater bottom fishing, Fly Fishing.
Main Targets: Giant Snakehead (Toman), Snakehead (Gabus), Hampala, Tilapia, Mahseer, Carp.
Preparation & Specialist Gear: Wear long sleeves (UV protection), a buff, and a wide hat, because sun exposure is high. In swamps a weedless froggy is essential so the lure does not snag on lilies. For shallow water, a belly boat or waders is more efficient.

Predators

Pick your target fish.

Learn the habits, habitat, and weaknesses of your quarry before you cast.

Giant Trevally (GT)
Caranx ignobilis
The most aggressive reef predator. Explosive power and extraordinary stamina in a fight. Its nickname: the gear-destroying monster.
Technique
Popping / Jigging
Habitat
Strong-current Reefs
Yellowfin Tuna
Thunnus albacares
A fast swimmer of the deep, running like a torpedo. The pull goes straight down and tests your gear and your back muscles.
Technique
Jigging / Trolling
Habitat
Open Deep Water
Monster Grouper (Kerapu)
Epinephelinae
The ruler of the reef bottom. It hides in holes and drags its prey straight into its lair. The first run is brutal and demands the skill to lock the line.
Technique
Bottom / Slow Jigging
Habitat
Underwater Reef Caves
Barramundi
Lates calcarifer
An estuary fish that goes acrobatic when hooked. Its gills are razor sharp and can cut the line without a strong leader.
Technique
Casting / Bottom
Habitat
Estuaries, Mangroves
Giant Snakehead (Toman)
Channa micropeltes
The most brutal freshwater predator in tropical waters. Its surface attack lands with a bang, then it drags toward branches or the roots of fallen trees.
Technique
Casting (Topwater)
Habitat
Lakes, Swamps, Rivers
Mahi-Mahi (Dorado)
Coryphaena hippurus
An acrobatic leaper with green-and-yellow colours that light up in the water. It swims fast in schools and strikes lures near the surface aggressively.
Technique
Trolling / Casting
Habitat
Open Sea (FADs)
Red Snapper (Kakap Merah)
Lutjanus campechanus
A greedy reef dweller. The first strike is powerful, then it runs straight for a gap in the coral. It needs tight drag and solid gear.
Technique
Bottom / Slow Jigging
Habitat
Deep Reefs, Shipwrecks
Hampala (Jungle Perch)
Hampala macrolepidota
A fast swimmer and guardian of the rapids. Its silver scales and horizontal black bar respond to a spoon or minnow pulled fast across the current.
Technique
Fast Casting
Habitat
Fast Rivers, Rocky Lakes
Large Tilapia (Nila Babon)
Oreochromis niloticus
The people's freshwater fish. Territorial about its nest. Landing a big "babon" tilapia takes patience, a sensitive float, and the right moss or pellet bait.
Technique
Negek (Pole) / Light Bottom
Habitat
Reservoirs, Lily Ponds, Ponds