THE HOLY GRAIL RISES
Christiaan Pretorius explores the phenomenon of dry-fly fishing for permit on the weed-rich flats of Xcalak
THERE IS a particular kind of madness that grips a fly-fisher in the weeks leading up to a big trip. You find yourself lying awake at night running through scenarios — the wind angle, the tide, the light. You tie flies you probably don't need, stare at weather apps obsessively, and bore everyone around you with stories they've already heard. As I write this, there is dried glue on my fingertips from a late-night tying session, and I wouldn't have it any other way. In a few weeks I'll be boarding the first of several flights that will deposit me, some thirty-odd hours later, in the small, sun-bleached village of Xcalak, on the very southern tip of Mexico's Yucatan Peninsula. It will be my third consecutive April there. And I already know that no amount of anticipation will fully prepare me for what I'm going to see.
Ready for action. Floating crab patterns stowed for their thirty-hour journey to permit heaven.
I've been lucky enough to pursue permit with a fly-rod in destinations across the world, and I've managed to catch all four species that can realistically be targeted on fly. They share a family resemblance — that high, compressed body, the deeply forked tail, the infuriating intelligence — but each fishery has its own character. I love them all for different reasons. And yet I keep coming back to Xcalak. Not just because of the permit, but because of what happens to them here in late April, in a convergence of wind, weed, and opportunity that feels less like fishing and more like witnessing something the natural world has been quietly rehearsing for a very long time.
Before I explain why, I should say something about permit in general, because if you haven't chased them before, it's difficult to convey quite what they do to you.
A permit — small, but with immense turn of speed and cunning.
You have to move like a heron, closing the distance without a ripple, without a shadow, without a sound
The fish that humbles everyone
Permit have earned their reputation as the holy grail of saltwater fly-fishing through decades of making fools of very accomplished anglers. They are not the biggest fish you'll encounter on the flats — a large permit might reach 15lb, though in some parts of the world fish pushing 40lb are a genuine possibility — but size is not really the point. The point is everything else.
They are bottom feeders by nature, most at home on reef edges and wrecks, rooting through rubble for crabs and molluscs. When they venture onto the flats they become visible — that great forked tail waving above the surface as they tip forward to root in the sand — and this is the thing that hooks you on permit fishing before you've even made your first cast. The sight of a large permit moving through ankle-deep water, dorsal fin cutting the surface, is genuinely one of the more extraordinary things a fisherman can witness. You have to move like a heron, closing the distance without a ripple, without a shadow, without a sound. Then you have to deliver a fly accurately, often at range, into the narrow window of the fish's attention. Then you have to hope.
Because hope is frequently all you have. A permit can inspect your fly with what feels like genuine intellectual curiosity, turn slowly, and leave the flat entirely. There is nothing wrong with your cast, nothing wrong with your fly, nothing wrong with your retrieve. The fish simply decided it wasn't interested, and permit don't negotiate. This is the dynamic that has given the species its reputation for difficulty. As such, it makes Xcalak's floating-crab season feel like a miracle.
Searching for surface-feeding permit in the gin-clear shallows.
A problem that became something else
The sargassum situation in the Caribbean is not a simple story, and it would be dishonest to dress it up as one. Over the past decade, accumulations of this free-floating brown seaweed have increased dramatically along the coastlines of Mexico, Belize, and the wider Caribbean. The causes are interconnected and largely man-made: agricultural fertilizer runoff — particularly from river systems draining into the Atlantic — has delivered enormous quantities of nitrogen and phosphorus into the ocean, essentially fertilizing the open water and allowing sargassum to bloom at scales that were previously impossible. Climate change compounds the problem through warmer ocean temperatures and altered circulation patterns. The result, most visibly since around 2018, is what scientists now call the “Great Atlantic Sargassum Belt” — a mass stretching thousands of kilometres across the tropical Atlantic that washes ashore each season in quantities that overwhelm beaches, impact reef systems, and cause real economic hardship for coastal communities.
For places like Xcalak, which has always prided itself on a certain remoteness and ecological integrity — the village sits within a national marine park — the annual arrival of sargassum is a genuinely difficult thing. When it decomposes in shallow water it depletes oxygen, releases hydrogen sulphide, and can stress the very marine systems that make the area worth visiting in the first place. This is a problem that deserves to be acknowledged plainly, not glossed over in the excitement of what it sometimes enables.
Extensive mats of floating sargassum on Xcalak, but it’s a man-made problem now seen across the wider Caribbean.
But here is where the story gets complicated in the best possible way. Sargassum has always, in its natural and historically modest quantities, served an important ecological function. Those open-ocean islands of weed are nursery habitat — juvenile fish shelter in them, sea turtles rest beneath them, and small crustaceans, including swimming crabs, live and feed within the tangled fronds. Historically, when sargassum washed ashore it brought this community of small creatures with it. What has changed is the scale. And what happens in Xcalak each April, when the trade winds shift onshore and vast mats of fresh sargassum begin moving across the flats, is that the crabs come with it. In enormous numbers.
When permit look up
Permit are bottom-orientated fish. Their anatomy tells you this; the mouth is positioned to root downward, the body designed to maintain station against the current while picking through rubble. The expectation, hardwired into most permit fly patterns, is that you are imitating something sinking, something crabbing across the bottom in the way that triggers a millennia-old feeding instinct.
The orange-brown swimming crab and Christiaan’s floating foam imitation.
What the floating crab season in Xcalak reveals is that permit are considerably more adaptable than their reputation suggests. With fresh sargassum blanketing the shallows, those small, orange-brown swimming crabs — the same species that have been living out their lives in the floating weed offshore — are suddenly everywhere near the surface, moving from clump to clump across the flat. And the permit, responding to an abundance of food that is not on the bottom but at the top, make an extraordinary adjustment. They rise. They begin searching upwards rather than downwards, swimming high in the water column, eyes tilted toward the surface, looking for the exact profile of a small crab moving in the film.
A moment that reorganises your understanding of what this type of fishing can be
If you have ever fished a dry-fly for trout, stood in a river watching a fish sip spent flies from the surface with metronomic precision, you will understand something of what it feels like to watch a permit do the same thing. But a permit is not a trout. It could be a fish of twenty-plus pounds, moving with a fluid, deliberate authority across a saltwater flat. Watching one slowly rise to the surface, tip its body upward, and sip in a foam crab fly is a moment that reorganises your understanding of what this type of fishing can be.
The first time it happened to me I was, I'll admit, barely functional. The cast was adequate. The presentation was decent. And then the fish simply came to the fly with a completeness and commitment that nothing in my permit-fishing experience had prepared me for. That memory doesn't go anywhere. It just lives in you.
Life is chilled on Xcalak, but the permit sport can be visual and explosive.
The first time it happened to me I was, I'll admit, barely functional. The cast was adequate. The presentation was decent. And then the fish simply came to the fly with a completeness and commitment that nothing in my permit-fishing experience had prepared me for. That memory doesn't go anywhere. It just lives in you.
The technique
The floating crab patterns that work in Xcalak are not complicated flies, but they require care. The goal is a small, buoyant crab profile, typically tied on a light-wire hook with closed-cell foam to ensure it sits in the film rather than on top of it, imitating the natural posture of a swimming crab suspended at the surface. Colour matters: the natural crabs are a mottled orange-brown, and flies that stray too far from this tend to get ignored. Legs and claws should suggest movement without being overdressed. The fly needs to land quietly.
Presentation is everything. You are fishing to sighted, surface-aware permit, which means the cast needs to land the fly with minimum disturbance, ideally just ahead of and in the path of the fish, close enough to be seen without being close enough to spook. Once it lands, you largely leave it. These are not retrieve-heavy situations. The fish come to the fly on their own terms, and the instinct to twitch and animate — natural enough in most permit fishing — can pull the fly away from a fish in the final moments of its approach. Patience and stillness are virtues here as much as accuracy.
They ask for precision, humility, and patience in proportions that most fishing does not require
What is particularly interesting is that this surface-feeding behaviour is not, it turns out, unique to Xcalak. Over the past three seasons I have had success with floating crab presentations in other permit fisheries. The fish adapt when the food is there. What Xcalak offers is the most reliable, concentrated window of this phenomenon that I'm aware of. The combination of geography, currents, and the annual sargassum bloom creates conditions that predictably produce surface-feeding permit for weeks at a time.
Delighted — and rightly so: a big permit taken in the surface on a floating crab.
What it means
I spend a great deal of time pursuing species that are considered the pinnacle of saltwater fly-fishing — giant trevally, tarpon, roosterfish, among others. Each demands something specific from you as an angler and offers something different in return. I have never had to choose between them, and I never intend to. But permit hold a particular place because of what they ask of you, even before the floating crab season makes them temporarily, gloriously, more approachable. They ask for precision, humility, and patience in proportions that most fishing does not require. And when you give them all of that and they still leave, you simply have to accept it and try again.
The floating crab season doesn't make permit easy. It makes them possible in a way that still feels like a gift. And every April, glue on my fingers and thirty-odd hours of travel ahead of me, I find that gift entirely worth chasing.
Christiaan’s tackle checklist
Here’s my set-up for fishing trips to Mexico.
Permit are my main focus in pretty much every scenario in Mexico — I’m a little obsessed. That said, I’m a fisherman first, so I always come prepared for other species too, especially tarpon.
Permit outfit: Loop 7X 9ft 8wt or 9wt, depending on the wind conditions and where I am in Mexico. I pair this with an Opti Speedrunner reel (I love the large arbor for speedy line recovery), typically loaded with Cortland’s All-Purpose Taper line — matched to the rod weight.
Tarpon outfit: Loop 7X 9ft 11wt for migratory tarpon, which I usually encounter during May–July (timing varies by location). I pair the 11wt with the Opti Gyre reel and like Cortland’s Tarpon Taper line for this set-up.
Leaders: This is really dependent on what you’re capable of casting and the conditions you’re facing.
For permit, I generally fish longer leaders in most situations — typically a 12ft (20lb) soft mono tapered leader, with 3ft of 15.9lb tippet added (sometimes longer and thinner if the fish are spooky). I’ll also extend my leaders when conditions are flat calm. When I’m fishing floating crabs, I prefer tapered leaders since they’re knotless and less likely to catch weed/debris.
For tarpon, I keep it simple — a straight section of fluorocarbon, anywhere from 60-80lb depending on the size of tarpon I’m targeting. I use Flouro for the abrasion resistance you need to withstand their sharp jaws. These fish generally aren’t picky about leader.
PHOTOGRAPHY & VIDEOGRAPHY: CHRISTIAAN PRETORIUS
ABOUT THE AUTHOR
Christiaan Pretorius
Christiaan Pretorius is an expert fly-fishing guide, competitor, and photographer who has cast lines across 39 countries for countless species — from the Seychelles to the wild rivers of Kamchatka.
