# How a billfish is released properly: circle hooks, the leader, revival and tagging

> A billfish in Costa Rica is released at the side of the boat without ever leaving the water: the crew grabs the leader and the bill, takes out the circle hook or cuts the leader close, and holds the fish facing forward until it kicks away. Done this way, studies put survival at about 9 in 10 for sailfish, and the law backs every step.

Source: https://sportfishing-costarica.com/how-to-release-a-billfish/
Last checked: 2026-11-15
The law: Billfish are released in the water; no lifting onto the gunwale for photos and no gaffs (INCOPESCA AJDIP/280-2014)
Hooks: Circle hooks are compulsory with natural bait; not required for fly fishing or lures without bait
Hook out: Remove the hook if you can; if not, cut the line as close to the mouth as possible
Survival: About 90% for sailfish released from sport boats (review of tagging studies, 2015)
Circle vs J hooks: Deep hooking 2% with circle hooks, 46% with J hooks (sailfish study, 2002)
Revival: Fish held facing forward, boat idling ahead, until it swims off on its own
Tagging: Free conventional tags from tagging programmes; ask before you book

## The short answer

In Costa Rica a sailfish or marlin is released without ever coming out of the water. When the leader reaches the boat, the mate takes hold of it, grabs the fish by the bill with gloved hands, and either backs the circle hook out of the jaw or cuts the leader close to the hook. Then the fish is held facing forward, with water running over its gills, until it kicks free and swims down on its own.

That sounds simple, and with a good crew it takes a minute or two. But every step matters for whether the fish lives, and most of them are written into Costa Rican rules. This page goes deeper on the release section of our [conservation and catch and release guide](/costa-rica-fishing-conservation/): what the law says, what the science says, and what you'll actually see happen at the side of the boat.

## What the law requires

Two INCOPESCA board agreements from 2014 set the rules, and they're short enough to summarise in full.

**AJDIP/086-2014** (the sport fishing chapter of the fisheries regulation) names the billfish (sailfish and marlin), tarpon and roosterfish as species of tourist and sport interest. All are catch and release, freed "in the least time and with the least harm possible". Billfish and tarpon must be released in the water without being brought aboard. The angler removes the lure, or with natural bait removes the hook, and if that isn't possible cuts the line as close to the fish's mouth as possible. Circle hooks are compulsory whenever natural bait is used for these species, and aren't required for fly fishing or for trolling artificial lures with no bait on them.

**AJDIP/280-2014** adds the handling rules. A live billfish caught by a sport or tourist boat is released by cutting the leader or line as close to the hook as possible, without taking the fish out of the water. Placing billfish on the gunwale for photos is banned, and so is using gaffs or hooks to pull them alongside. The only exceptions are a fish being documented for a world record and catches in tournaments approved by INCOPESCA.

So in plain terms: circle hooks with bait, the fish stays wet, no gaff, no "hero shot" over the rail.

![A single silver circle hook bent into an almost closed C shape, its point turned inward, tied to clear heavy line on a wet white deck](/static/img/rbf-circle-hook-800.webp)

## Before the bite: gear that makes release easier

### Circle hooks, and how to fish them

A circle hook's point curves back toward the shank. When a fish swallows the bait and swims off, the hook slides back out of the throat and rolls into the corner of the jaw. The best-known test was done just up the coast, off Iztapa in Guatemala, on 360 Pacific sailfish:

| Result | Circle hooks | J hooks |
|---|---|---|
| Hooked in the corner of the mouth | 85% | 27% |
| Hooked deep, in the throat or stomach | 2% | 46% |
| Foul hooked (outside the mouth) | 1% | 9% |
| Hook-related bleeding | 21 times less likely | |

The circle hooks also converted bites into hookups 1.83 times as often, which is why crews here have no complaints about the rule. The catch is technique. With a circle hook you don't strike. The mate drops the bait back, you let the fish eat, then lock up the reel and let the line come tight as the fish swims away. Jerk the rod and you'll pull the hook straight out of its mouth. Our [techniques guide](/costa-rica-fishing-techniques/) explains the drop-back in more detail.

### Leader and tackle

Lighter line makes a longer fight, and a long fight leaves a fish exhausted, full of lactic acid and easy prey for sharks. MarViva's 2023 Costa Rica best-practices guide puts it simply: match the tackle to the fish so the fight is short. For sailfish most boats here fish 20 to 30 pound class, which balances sport with a fish that's still lively at the boat.

The leader is the stretch of heavier line between the main line and the hook. It's what the mate grabs. IGFA rules cap leader length (for line over 20 pounds, 30 feet) and the mate's handling of it, which matters if you're chasing a record. For everyday fishing, the point is that the mate needs a leader long enough to get a grip on before the fish is within reach.

## At the boat: step by step

Here's what a good release looks like, drawn from MarViva's guide, the IGFA's release guidelines and The Billfish Foundation's tag and release guide.

::: triptych "The release kit"
![A pair of heavy grey fishing gloves with textured palms on the white gunwale of a boat beside a coiled leader](/static/img/rbf-gloves-800.webp)
![A pair of long-nosed stainless steel fishing pliers lying on a wet white boat deck](/static/img/rbf-pliers-800.webp)
![A tagging stick with a stainless steel tip holding a small dart tag with a bright orange streamer, on a wet white boat deck](/static/img/rbf-tag-stick-800.webp)
:::

1. **The captain closes the distance.** Backing the boat toward the fish, or turning to keep it on the right side, cuts minutes off the fight. That's the single biggest thing a crew does for the fish.
2. **The mate takes the leader.** In most tournaments this moment, when the mate touches the leader or the leader reaches the rod tip, already counts as a release. Wearing gloves, the mate brings the fish alongside hand over hand, keeping the line clear of hands and feet.
3. **Control the bill and the body.** Once the fish is close and calm, the mate grabs the bill with both hands, sometimes with a second crew member steadying the body. The fish stays in the water the whole time. The Billfish Foundation warns that lifting a fish, even onto the gunwale, strains its skeleton and organs, and that rubbing strips its protective slime.
4. **Hook out, or leader cut.** A circle hook in the corner of the jaw usually backs out in seconds with pliers or a dehooker. If it's deep, or the fish is thrashing, cut the leader as close to the hook as possible. Costa Rican rules and the IGFA agree on this, and MarViva notes that fish with a swallowed hook left in survive better than ones where crews dig for it. Never pop the line by pulling until it breaks.
5. **Check for a tag.** Before letting go, look for a tag streamer near the dorsal fin. If there is one, The Billfish Foundation asks you to cut off only the streamer, note the fish's size and position, and report it.
6. **Revive it.** Hold the fish by the bill, head into the water, while the boat idles slowly forward, so water flows over the gills. Never pull it backward. The IGFA advises gently moving a tired fish forward and taking as long as it needs, and The Billfish Foundation says that can be a couple of minutes or longer. When its colour brightens and it starts to pull, let go.
7. **Watch it go.** A healthy fish swims down and away. If it rolls or sinks, catch it again and keep reviving.

![A blue marlin with a cobalt back and pale vertical stripes swimming away fast through clear deep blue water lit by shafts of warm sunlight](/static/img/rbf-blue-marlin-800.webp)

### Marlin are different

Everything above applies, but a blue marlin can weigh several hundred pounds and is far more dangerous at the boat than a sailfish. Crews take the leader more carefully, often leave the fish in the water well away from the hull, and cut the leader sooner rather than wrestle with a hook. Back in 2009, the Tico Times quoted Todd Staley of Crocodile Bay saying a marlin dragged aboard is almost sure to die. That's one reason Costa Rican crews moved away from lift-out photos years before the rules required it.

## The photo

You can still get a great picture. It just has to be taken with the fish in the water, which is what the law asks for and what the best crews here are good at.

- **Tell the crew before the fish is hooked** that you'd like a photo, so the person with the camera is ready.
- **Lean over the side,** with the mate holding the bill, for a shot of you and the fish together at the surface. Some crews let the angler hold the bill for a moment with gloves.
- **Keep it quick.** A few frames, then the revival. The fish's time matters more than the tenth photo.
- **Shoot from the bridge or with a pole camera** for the classic top-down view of a lit-up sailfish beside the boat.

What you shouldn't ask for is a fish lifted over the gunwale. It's illegal for billfish here outside records and approved tournaments, and a good captain will say no.

## Do released billfish survive?

Most do, when they're handled well. A review of more than 40 tagging studies by Michael Musyl and colleagues, published in 2015, estimated that about 86% of billfish released from recreational boats survive, and about 90% of sailfish (7 deaths among 85 tagged fish). Most of the deaths happened within minutes to a few days. Single-species work points the same way on hooks: in one white marlin study, every fish caught on a circle hook survived, against about 65% on J hooks.

![A Pacific sailfish swimming down and away into deep blue water, its tall spotted sail running the whole length of its back](/static/img/rbf-sailfish-free-800.webp)

Costa Rican sailfish are tough travellers when they recover. Satellite tags put on 9 sailfish from recreational boats off Costa Rica in 2008 and 2009 tracked 6 of them for 340 to 986 km, across the waters of 6 countries, which our [sailfish page](/the-pacific-sailfish/) covers. Release is only part of the story, though: a 2023 study found peak-season sailfish numbers well down since 2011, mostly from commercial longlining. A good release keeps one fish in the sea; the rest takes policy.

## Tagging your fish

A conventional tag is a small dart with a numbered streamer, put into the fish's back with a tagging stick while it's still in the water. If the fish is caught again, the new captor reports the number, and scientists learn where it went and how it grew.

![A gloved crew member leaning over the side to steady a sailfish in the water, a satellite tag and a yellow streamer tag in its back](/static/img/rbf-noaa-tagging-800.webp "Photo: [Tagging a large billfish](https://commons.wikimedia.org/wiki/File:Fish0260_-_Flickr_-_NOAA_Photo_Library.jpg) by Derke Snodgrass, NOAA, public domain, via Wikimedia Commons")

- **Where the tag goes.** The Billfish Foundation's guide says to aim for the thick muscle of the back, behind the head and gill covers, above the lateral line and away from vital organs, with one firm, well-aimed push. Never tag a fish that's jumping or thrashing.
- **Who provides tags.** Gray FishTag Research gives participating captains tags and research cards free, and anglers log the release on its website. The Billfish Foundation runs its own programme with online reporting, and NOAA's Pacific programme has collected angler tag data since 1963.
- **How to arrange it.** Ask your operator before you book whether they carry tags and report them. Many of the bigger fleets on the Central and Southern Pacific do.

## How to tell a good crew

You'll learn a lot about a boat in its first release. Signs of a crew that knows what it's doing:

- They talk about circle hooks and the drop-back before the lines go out.
- The captain works the boat to keep the fight short.
- The mate wears gloves, takes the leader smoothly and keeps the fish in the water.
- They cut the leader without hesitation when the hook's deep.
- They revive the fish facing forward and don't let go until it swims.
- They ask whether you'd like to tag, and know where to report it.

If you're choosing a boat, our zone guides for the [Central Pacific](/central-pacific-fishing-guide/), [Southern Pacific](/southern-pacific-fishing-guide/) and [Guanacaste](/guanacaste-fishing-guide/) name operators, and our [Central Pacific sailfish season guide](/central-pacific-sailfish-season/) covers the best months. The same handling skills apply to any shark you hook, which our [guide to sharks and the rules](/sharks-costa-rica-fishing-rules/) explains, and the bigger picture is in our [conservation guide](/costa-rica-fishing-conservation/).

## Frequently asked questions

### Can I take a sailfish out of the water for a photo in Costa Rica?

No. INCOPESCA's rules ban putting billfish on the gunwale for photos, and the fisheries regulation says they must be released in the water. The only exceptions are world-record fish and INCOPESCA-approved tournaments. Take your photo with the fish beside the boat.

### Are circle hooks required in Costa Rica?

Yes, whenever you fish natural bait for billfish, tarpon or roosterfish. They aren't required for fly fishing or for trolling artificial lures without bait.

### Should the hook be removed or the leader cut?

Remove it if it comes out easily, which a circle hook in the jaw usually does. If it's deep or the fish is thrashing, cut the leader as close to the hook as possible. Costa Rican rules allow either.

### How long does it take to revive a billfish?

Often a minute or two, sometimes longer after a long fight. The fish is held facing forward while the boat idles ahead, and released when it brightens and pulls on its own.

### Do released sailfish survive?

About 9 in 10 do, according to a 2015 review of tagging studies, as long as they're handled well. Short fights, circle hooks and keeping the fish in the water make the biggest difference.

### Can I tag a billfish on my charter?

Often, yes. Ask your operator before you book whether they carry conventional tags from a programme such as Gray FishTag Research or The Billfish Foundation, and whether they report releases.