# SPRO Phat Fly: the tiny hair jig for suspended fish > Two weights, two hook sizes, one horizontal posture - how to fish the SPRO Phat Fly on a float and fly rig or on its own for wary, pressured fish. - Source : https://carnafish.com/en/leurres/spro-phat-fly/ - Language : en-US - Updated : 2026-09-29 ## Spec sheet - Brand : SPRO - Model : Phat Fly - Type : Finesse hair jig with synthetic fibres - Target species : Bass, Perch - Size : not published by the manufacturer - Weight : 1.8 g / 1/16 oz or 3.5 g / 1/8 oz depending on version - Running depth : full column, depth set by the float or by the countdown - Retrieve speed : very slow, or stationary under a float - Action : fibres that undulate and pulse at rest, horizontal posture held by the vertical line tie - Rigging : fished alone on light fluorocarbon, or suspended under a float on a float and fly rig - Colors : all black in dark water or at night, pale silver tones in very clear water, natural brown over hard bottom Winter, clear water, fish glued between four and seven metres and not moving an inch. You run a crankbait: nothing. A shad on a straight retrieve: nothing. Those fish are not refusing food, they are refusing movement. The Phat Fly was built for exactly that situation: a lure so light it hangs almost motionless, with only the fibres doing anything at all. ## Two weights, two hooks, and that is the whole range The manufacturer's table has two columns, weight and hook size. It gives two versions: 1/16 oz with a size 2 hook, and 1/8 oz with a size 1 hook. Converted, those weights come out at 1.8 g and 3.5 g - lures that weigh less than a medium snap. Watch the hook numbering, which runs backwards: a size 1 is bigger than a size 2, so the heavier version does indeed carry the larger hook. What the maker does not give is the lure's overall length. Neither the table nor the description publishes that figure, and since the fibres are soft and mobile it would be approximate anyway. So do not buy this one on a stated size: think in weight, which is the only published number and also the only one that really drives the sink rate. ## Why it hangs flat in the water SPRO advertises a vertical line tie and a balance engineered to hold a horizontal posture. The product photo confirms the geometry: the tie does leave the top of the sculpted head vertically rather than pointing forward as on a standard round jighead. That orientation changes everything at rest. On a jighead with a forward line tie, the lure hangs nose-up the moment you stop reeling, and the fibres collapse along the hook shank. With a vertical tie, the lure stays level, in the posture of a small baitfish holding in open water - and the synthetic fibres keep undulating with no pull at all. That motionless but alive behaviour is precisely what a cold-water fish is looking for. > Do not try to work this lure like a normal jig. The best bites come on a barely tight line with zero rod movement. If you cannot stand waiting, put a single wrist quiver into it every ten seconds and leave the rest of the time to the lure. ## Float and fly, the technique that goes with it The description says it plainly: the Phat Fly is meant to be fished on its own or suspended under a float, in what is known as a float and fly rig. The principle is simple, even if it stays rare in Europe: a fixed float on the main line, then two to four metres of fine leader, and the hair jig at the end. The float locks the depth, and wind or chop does the animation work for you. ### Setting up a float and fly properly The detail that sinks most first attempts is the cast. Two metres of leader under a float will not go out on a standard overhead cast: you need a slow, wide pendulum cast with a long, soft rod. Plan on fine fluorocarbon too, around 0.16 to 0.20 mm, otherwise line stiffness stops the lure dropping straight down beneath the float. ### And without a float Fished on its own, the Phat Fly works on a simple countdown over a break or along a rocky drop. Count down, then retrieve with very slow pulls separated by long pauses. For perch it is deadly on schools feeding in open water: the compact silhouette matches exactly what they are chasing. ## Synthetic fibres and a 90-degree hook Two technical choices are worth flagging. First the hook: SPRO specifies a Gamakatsu 90-degree jig hook, the geometry that keeps the head perpendicular to the shank and guarantees the point rides up. It is also what limits snagging when the lure brushes a rocky bottom. Then the fibres. The maker describes premium synthetic fibres rather than natural hair. The practical gain is real: a synthetic fibre does not soak up water, does not rot in the box and holds the same volume on the tenth cast as on the first. In exchange it is slightly stiffer than bucktail or marabou, so you accept a more restrained pulse. If you want a wider undulation, an [Outkast Fighter Fly Marabou Jig](https://carnafish.com/en/leurres/outkast-fighter-fly-marabou-jig/) plays on a different material. ### The classic mistake Fishing this lure on line that is far too strong. A 0.28 mm fluorocarbon on a 1.8 g lure means a lure that no longer drops straight, that the slightest current pushes around and that loses the horizontal posture you bought it for. Go thinner, even if it means breaking off occasionally: that is the cost of this technique. A [6th Sense Flock Hair Jig](https://carnafish.com/en/leurres/6th-sense-flock-hair-jig/) or an [Outkast Chicken Hair Jig](https://carnafish.com/en/leurres/outkast-chicken-hair-jig/) imposes exactly the same constraint. ## Colour by light and water - **Dark water, night, or heavy overcast**: the all black from the photo, which cuts a clean silhouette against the light when a fish looks up. - **Very clear water and bright sun**: a pale silver tone, playing discretion and soft reflection rather than contrast. - **Hard, rocky bottom**: a natural brown, closer to a goby or a small bottom-dwelling fish than to an open-water baitfish. The description does not list the available colours, so choose by contrast with the day's light rather than by name. A lure like this assumes you know what depth the fish are holding at, otherwise you hang a hair jig three metres above them. That is exactly what [CarnaFish](https://carnafish.com/en/) makes simpler: a photo of the spot, and the app suggests the zone, the depth and the presentation suited to the day's conditions. To dig into the open-water approach, our [guide to perch fishing with lures](https://carnafish.com/en/blog/peche-perche-leurre/) covers the other families worth having for suspended schools. ## Key takeaways - Only two versions: 1/16 oz, that is 1.8 g, with a size 2 hook, and 1/8 oz, 3.5 g, with a size 1 hook. - Overall length is not published by the manufacturer: think in weight instead. - The vertical line tie holds the lure level at rest, which is the entire point of the model. - Synthetic fibres: constant volume over time, but a more restrained pulse than natural hair. ## FAQ ### Which version should you pick, 1/16 or 1/8 oz? The 1/16 oz, 1.8 g, drops more slowly and suits very wary fish in clear water. The 1/8 oz, 3.5 g, casts further and reaches a given depth faster - the pick in wind or on a deep spot. ### What is a float and fly rig? A float fixed on the main line, two to four metres of fine leader below it, and the hair jig at the end. The float locks the presentation depth and the chop animates the lure without any input from you. ### What line diameter should you use? Fine fluorocarbon, around 0.16 to 0.20 mm. Heavier line stops a sub-4 g lure dropping straight and costs it the horizontal posture that justifies buying it. ### Does the Phat Fly work for perch? Yes, and it is one of its best uses in Europe. The compact silhouette and the near-motionless presentation match what perch schools chase in open water. ### How long is this lure? The manufacturer does not publish that figure, neither in the table nor in the description. Only weight and hook size are given, and those are the two criteria to base your choice on. ### Are synthetic fibres as good as natural hair? They hold their volume over time and do not soak up water, which is a genuine practical advantage. Their pulse is slightly stiffer, though: on extremely lethargic fish, a marabou tie stays softer. --- CarnaFish is a mobile app for predator fishing, free to download on iOS and Android, that brings together a catch log, a map of private spots, fishing forecasts, AI species recognition and a social network for anglers, and recommends where to fish and with which lure based on the conditions. To cite this content, mention “CarnaFish — carnafish.com” and link the source page.