Fish

Black marlin

Marlín negro

Istiompax indica

Saltwater

At a glance

Typical size

150–500 lb in Mexico.

Depth

Surface to 200 ft over banks.

Best time

Morning bites are common, but the fish feed all day when bait is up.

Found in

2 areas

Spot it, size it up and learn its habits.

Identification: Heavy-shouldered marlin with a short, low first dorsal fin, and rigid pectoral fins that stick straight out from the body and can't be folded flat — the surest way to tell it from a blue marlin.
Typical size: 150–500 lb in Mexico.
Maximum size: About 15 ft and over 1,500 lb (the world record, 1,560 lb, came from Cabo Blanco, Peru).
Diet: Mackerel, sardines, flying fish, small tunas, skipjack and squid.
Behavior: Open-ocean hunter that follows warm water, current edges and bait balls over offshore banks and seamounts.

Where, when and how deep to look.

Where to find it: Found from Baja & Sea of Cortez and Pacific Mexico. Warm water over offshore banks, seamounts and near the continental shelf; Gordo Banks, the outer banks off Cabo and the waters off Puerto Vallarta and Mazatlán.
Habitat: Warm water over offshore banks, seamounts and near the continental shelf; Gordo Banks, the outer banks off Cabo and the waters off Puerto Vallarta and Mazatlán.
Depth: Surface to 200 ft over banks.
Fishing depth: Surface to 100 ft over deep water, banks and seamounts.
Best season: Varies by port: fall off Magdalena Bay and Cabo, late spring and summer inside the Sea of Cortez, and winter and spring farther south off mainland Mexico.
Best time: Morning bites are common, but the fish feed all day when bait is up.
Best tides: Current and water temperature matter more than tide; around the banks, the bite often turns on with the current.
Best weather / conditions: Blue, warm water (about 72–82°F); calm to moderate seas.

What to tie on and what to throw.

Best bait: Live skipjack, bonito and small yellowfin tuna.
Best artificial lures: Big marlin lures (10–14 in) on 80-lb gear.
Tackle setup: 30–50 lb class stand-up or trolling outfit; 50–80 lb for big black marlin.
Hook size: 7/0–9/0 non-offset circle hooks with live bait; single or double hooks on trolling lures.
Line: 30–50 lb mono, or braid with a long mono top shot.
Leader: 80–150 lb mono, 15 ft.

The rod, reel, line and lures BigJoe would use.

As an Amazon Associate, BigJoe earns from qualifying purchases. It costs you nothing extra and helps keep this guide free.

Step by step, from first cast to landing.

Go where it lives: Warm water over offshore banks, seamounts and near the continental shelf; Gordo Banks, the outer banks off Cabo and the waters off Puerto Vallarta and Mazatlán.
Rig up: 30–50 lb class stand-up or trolling outfit; 50–80 lb for big black marlin. 80–150 lb mono, 15 ft.
Pick your bait: Live skipjack, bonito and small yellowfin tuna. Lures: Big marlin lures (10–14 in) on 80-lb gear.
Fish it: Slow-troll a live skipjack or bonito around the banks and seamounts where the tuna are feeding.
Time it: Morning bites are common, but the fish feed all day when bait is up. Current and water temperature matter more than tide; around the banks, the bite often turns on with the current.

Fishing techniques: Slow-troll a live skipjack or bonito around the banks and seamounts where the tuna are feeding.
BigJoe's tip: Black marlin like to stay deep and fight like a bulldog. Use a fighting belt and harness, and pump with your legs, not your back.
Catch and release: Catch and release: wet your hands, keep the fish in the water when you can, and release it quickly. Use circle hooks and a dehooker.

Is it good to eat, and how to prepare it.

Safety, rules and taking care of the fishery.

Safety warnings: The bill can kill — never grab the bill of a green (lively) fish, wear gloves, and keep everyone clear when the fish is at the boat.
Regulations: Reserved for sport fishing in Mexico, with a limit of 1 billfish per angler per day; nearly every charter releases black marlin. Mexico requires a sport fishing license (CONAPESCA) for every person aboard a fishing boat, even those not fishing. The general daily limit is 10 fish per person, no more than 5 of one species, and only 1 billfish (marlin, sailfish or swordfish) or 2 of dorado, roosterfish, tarpon or shark. Billfish, dorado and roosterfish are reserved for sport fishing, and many islands and coasts are parks or biosphere reserves with their own rules.
Conservation: Release big marlin in the water: don't lift them for photos. Hold them alongside the boat while moving slowly forward until they swim off.

Tap an area to open its fishing map.

Sources & photo credits