Summer in Amami Oshima
Big Dipper
GT Casting Fishing Trip

Article Contributor
Rin Kobayashi (Shimano Support Angler)
Resides in Saga Prefecture. Using the fish-rich Genkai Strait as his home field, he pursues memorable encounters with fish through both offshore and shore fishing. He is well-versed in a wide range of fishing styles, from big game to light game, and shares the charm and enjoyment of fishing with many people.

My Passion for GT

The area stretching from Amami Oshima to the Tokara Islands boasts a proven track record of landing large GT and is considered one of Japan’s premier GT fishing grounds. In the summer of 2025, I had the opportunity to embark on an expedition to this very place, targeting GT with casting gear.

For me, GT is a target fish I continually challenge myself to catch, setting goals along the way. I became hooked on fishing as a child and started serious sea bass fishing in junior high. Later, during my junior high years, Captain Seiichirou Tashiro of the popular charter boat Sunrise, who lived nearby, took me out for my first yellowtail amberjack casting trip. The intense bite I experienced then hooked me on offshore casting.

Since then, I’ve repeatedly gone fishing, chasing big fish through offshore casting and shore (rock) casting games. Among these targets, GT stood out as particularly challenging to conquer yet incredibly alluring, sparking my interest and a strong desire to land a large one. Witnessing my first GT strike gave me goosebumps – it was that shocking. I remember my curiosity exploding then – what kind of strike would an even bigger GT deliver? How powerful would its pull be? From that moment on, I set my goal at 50kg and kept challenging myself. To achieve that goal, I boarded the popular GT boat Big Dipper in Kagoshima’s Amami Oshima this time. Under Captain Kenzaburo Fukui’s helm, I embarked on a 3-night, 4-day challenge seeking large GT. I’d like to share how that challenge unfolded.

Day One: Opening with Consecutive Strikes

Due to flight schedules, our first day of fishing began with a midday departure. With limited fishing time, we started exploring waters near Amami Oshima. The group assembled at the port, quickly prepared, and set sail. Our first spot was about an hour’s run from the harbor. Winds were blowing near 10 meters per second, creating an exceptional atmosphere right from the first location. Our excitement grew even more as the GT casting expedition commenced.

Since this spot was new to me, I first selected my trusted Shimano Wild Response 240. This lure is indispensable to me; it’s a model I deeply trust, having landed numerous personal record-sized fish for me. Its wide body and big silhouette provide outstanding appeal, and it handles jerks perfectly from short to long. Furthermore, its 137g weight ensures stable flight posture and solid distance even when casting against the wind using PE10 tackle, making it an extremely reliable lure.

Then, on the very first cast, a GT delivered a fierce bite. However, I couldn’t hook it up, so I cast again. Another fierce strike followed, and this time I hooked it solidly. But during the fight, while maneuvering around the boat’s hull, it unexpectedly hooked out.

The high activity continued afterward, resulting in 6 hits. However, every one hooked off, leaving me unable to land a fish. Seeing my frustration, the captain explained, “The GTs are so active they’re just grazing the hook.” Since I had the drag set fairly tight, it seemed they were breaking off during the fight.

In the end, I didn’t land any fish that day. The GTs were highly active, and there were many chances, but it was a frustrating day.

Big Dipper is a charter boat operated by Kenzaburo Fukui, one of Japan’s top GT anglers. He owns three boats, piloting the largest, the 70-foot No. 3 vessel himself. He is a reliable captain who knows the GTs of Amami Oshima and Tokara inside out.

The Big Dipper office on Amami Oshima. It’s a place full of charm for GT anglers, bearing the history of GT fishing aboard Big Dipper boats.

Day Two: Fishing in Dead Calm

Day two dawned with no wind, and we set out in dead calm conditions. We started first thing at the spot that had been productive the previous day. The dead calm suggested it would be a tough day. However, despite the calm, the current was flowing nicely from the morning, so we remained optimistic, thinking there might be one chance, and began casting.

I selected the Shimano Wild Response 240F lure, which had gotten consecutive bites the previous day. I switched it to a single hook setup. Since all fish hooked with the treble hook the day before had come off, changing to a single hook aimed to ensure a solid hookset in the gill plate and prevent losses.

However, unlike the previous day, the sea had turned completely silent with absolutely no fish response. So the captain decided to move on early, heading for a shallow area. In this shallow zone, I worked the Wild Response 240F with stronger jerks than usual to make it stand out more and appeal over a wider area, using short jerks for the action. The current was flowing nicely, and the atmosphere felt promising. Just a few casts in, I got a bite from the target GT. But again, I couldn’t get it hooked.

After that, we continued casting while experimenting with various lure actions, but there was no response from the fish. As a result, the second day of fishing ended with just one chance. It was a day that made us keenly aware of the difficulty of fishing in dead calm conditions.

Day Three: Our First Trip to the Tokara Islands

Day three dawned with no wind and dead calm seas again, plus the scorching heat typical of summer on Amami Oshima. Based on the conditions from the previous two days, we decided to change locations significantly for day three, heading straight to Yokoate Island, the southernmost point of the Tokara Islands, first thing in the morning. This was my first GT fishing trip in the Tokara Islands, and I couldn’t contain my excitement during the trip there. Upon arriving at the spot, even before casting a line, I felt “just being here was worth it” as an incredibly beautiful view, unlike anything I’d ever seen before, spread out before me.

For this day, I selected Shimano’s new product, the Dive Flat 200F (scheduled for release in Fall 2025), and started with a treble hook setup. When I used a prototype model for yellowtail casting in the spring, I experienced a series of bites unlike anything I’d ever felt before, leading me to believe it might also be effective for GT, hence my selection.

The signal to start came at a shallow point teeming with baitfish. Despite the atmosphere suggesting GT could surface at any moment, they stubbornly stayed below. Time passed with no bites, forcing us to move spots around noon.

At the next spot, I again selected the Dive Flat 200F. The Dive Flat 200F produces a different action than the Dive Flat 240F, with a quick, sharp movement. It gives the impression of being versatile depending on how you work it. With its easy-to-handle size, the intense flash from its flat sides, and the rattle sound, I feel it’s a diving pencil that excels not only for GT but also for yellowtail amberjack and other fish.

Later, at a point with submerged rocks, I worked the Dive Flat 200F with quick, short jerks. A small GT chased it, then delivered a fierce strike. Whether drawn by the Dive Flat 200F’s high appeal or simply attacking aggressively, it was a solid bite, but again, I couldn’t hook it. As a result, despite GT activity on the third day of fishing, I ended without a catch. Considering the GT’s high activity on the first day, I expected to catch them on the second and third days. However, GT casting proved difficult, and I realized they aren’t fish that bite easily. I pinned my hopes on the final day.

At the very end of the final fishing day

The final day also started with a light breeze and almost dead calm. Getting no response at the first spot of the morning, I moved to a point with a steep drop-off. With water depth around 30m and current present, I selected the Shimano Colt Sniper Pegma 200HS.

This lure, developed for shore big game fishing rather than offshore, is a sinking minnow. I chose it because it can search deeper layers. After a full cast, I let it sink for 25 counts, then retrieved steadily. Suddenly, a solid “thud” bite in the mid-water layer. For a moment, I thought it was GT, but reeling it in revealed a beautiful, good-sized bluefin trevally. Not my target species, but finally catching a fish typical of southern waters brought me relief.

A bluefin trevally hooked on the heavy sinking minnow Colt Sniper Pegma 200HS Jet Boost. Though marketed for shore fishing, it proves effective offshore too. A reliable lure when topwater lures get little response. The HS weighs 120g, with the 170g 200XS model also available for deeper water.

As the fishing trip neared its end, we moved to a final spot. Since it was a location with intense tidal waves, I switched back to the Wild Response 240 lure. The reason was twofold: it flutters effectively even in strong waves, and I wanted to finish strong with a lure I was comfortable using.

Then, after Captain Fukui announced “three more drifts left,” I got a fierce bite just as we hit the swell. Fighting it carefully, I succeeded in landing a beautiful, good-sized GT right at the very end. It was an incredibly moving fish, rewarding the three days without a catch.

Even in a top-tier domestic field, GTs aren’t easy to catch. That’s precisely why the joy when you land one is extraordinary. This trip reaffirmed my desire to keep casting for GTs, aiming for bigger sizes.

Near the end of the final day, a hit on the familiar Wild Response 240. Carefully working through its powerful resistance to bring it in.

Finally, I’d like to introduce the tackle I prepared for this fishing trip. The rods I brought were three types: the Shimano “25 Ocea Plugger Limited S83H,” the “24 Ocea Plugger Full Throttle S82XH-3,” and the “24 Ocea Plugger Full Throttle S83MH-3.”

My main rod is the 25 Ocea Plugger Limited S83H. Its higher modulus performance compared to the Full Throttle makes it easier to swing through even in windy conditions, enabling stable casting distance. The stiffness extending to the tip also provides excellent lure control, making it easy to handle plugs up to about 100-130g, even those with strong vibrations. The high-modulus, stiff power from the belly to the butt section allows the rod to simply stand firm and withstand pressure, using its rebound to lift the fish to the surface.

The 24 Ocea Plugger Full Throttle S83MH-3 is designed for casting smaller lures. Unlike the H-class, it maintains moderate stiffness throughout the tip section while still handling smaller lures (around 70-90g) with precision, making it essential for GT casting. Despite being MH, its powerful butt section effectively brings fish to the surface.

Furthermore, the 24 Ocea Plugger Full Throttle S82XH is a power model designed for using large lures or tackling shallow areas. It excels when high drag resistance is needed to withstand runs in shallow reef points where snagging is a risk. This rod is exceptionally user-friendly when using large lures from 130g to 180g or lures with high retrieve resistance.

By the way, for PE line, I selected the “OCEA 17+” across the board. This PE line features a core within its 16-strand construction, providing just the right amount of stiffness and minimizing tangles. Furthermore, even after casting all day, it resists fraying, reducing breakage concerns and cutting down on the number of times you need to re-tie knots. I find it to be an exceptionally excellent line to use and highly recommend it.

I hope this serves as a useful reference when selecting your tackle for your next fishing trip.

GT caught. It’s precisely because it’s not easy to catch that it’s valuable and appealing.

[Rin Kobayashi’s Tackle]

Tackle ①

Rod: Shimano 25 Ocea Plugger Limited S83H

Reel: Shimano 25 Stella SW 14000XG

Line: Shimano Ocea 17+ No. 8

Leader: Shimano Ocea Nylon Casting Leader 140lb

Lure: Shimano Wild Response 240F

Hook: Gamakatsu Plugging Single World Recorder 9/0

Tackle ②

Rod: Shimano 24 Ocea Plugger Full Throttle S82XH-3

Reel: Shimano 19 Stella SW 14000XG

Line: Shimano Ocea 17+ No. 8

Leader: Shimano Ocea Nylon Casting Leader 140lb

Lure: Shimano Pegma 200HS

Hook: Gamakatsu GT Recorder 4/0

Tackle ③

Rod: Shimano 24 Ocea Plugger Full Throttle S83MH-3

Reel: Shimano 21 Twin Power SW 14000XG

Line: Shimano Ocea 8 PE No. 6

Leader: Ocea Nylon Casting Leader 120lb

Lure: Shimano Dive Flat 200F

Hook: Gamakatsu Treble SP-XH 4/0

Fishing Boat: Big Dipper　https://bigdipper-amami.com/

Text: Rin Kobayashi
Summary: Anglers Time Editorial Department