Chasing the Impossible Shot: The Untold Story of How I Filmed an 800lb Giant Bluefin Tuna Devouring a Bluefish Underwater

Traditional tuna fishing gives you the fight, but it doesn't give you the story. I wanted the story I'd been dreaming about for decades.

So I made a decision that shocked my Dad and a lot of people who knew me: I traded my fishing setup for an underwater camera system. No hooks, no intention to catch. Just a camera, 20-pound leader, and a hope that I could capture something unprecedented in the waters off Cape Cod—something I'd wondered about since I was a kid staring out at the ocean.

Trip One: So Close, Yet So Far Away (September 8, 2023)

My first attempt at filming a giant tuna devouring a bluefish underwater was both exhilarating and heartbreaking—though I wouldn't know it until I got home.

I was fishing with my dad Jake that day, which made it extra special. Over the years, Dad and I have spent hundreds of hours on the water together, but nowadays we don't get out as often as we once did. The goal was simple: catch some bluefish, then slow-troll them behind my underwater camera (without a hook) in hopes of capturing a giant tuna bite on video.

I think my Dad was shocked at first to hear we'd be fishing without hooks! But it made sense—I was only looking to capture an image, not a fish. We started the morning by catching stripers at Scorton Ledge in Cape Cod Bay, then switched gears to catch bluefish for bait.

I rigged up a beautiful 30+ inch bluefish on 30-pound test Trilene monofilament leader and sent it down about 30-40 feet beneath the surface. We were slow trolling in roughly 95 feet of water in Cape Cod Bay, the camera positioned about 6 feet from the bait.

Hours passed with no indication anything was happening below. No rod bends, no line pulling, nothing.

It wasn't until I got home and reviewed the footage that I saw it—a giant bluefin tuna, perhaps more than 500 pounds, came over to investigate my bluefish. The massive predator circled, studied, and came close enough to strike. My heart pounded watching the replay, seeing how close I'd come to capturing the shot I'd dreamed about since childhood.

But the tuna didn't commit. It investigated and swam away.

Lesson learned: Getting a giant tuna to investigate is one thing; getting it to bite is entirely different. Watching the footage carefully, I realized the bluefish didn't look natural—I had bridled the bluefish behind the head, which would have been fine if we were anchored or slowly drifting. However when slow trolled the bluefish was being pulled in an awkward way through the water, and I think the tuna may have been turned off by this.

I was simultaneously encouraged and frustrated. The giants were there. They were curious. But my setup needed work.

Trip Two: Three Giants Investigated But Wouldn't Commit (September 13, 2023)

If the first trip was a surprise, the second was pure heartbreak.

I spent the entire day on Cape Cod Bay without any indication that anything remarkable had happened. No dramatic rod bends, no line peeling off the reel, nothing. I headed home that evening figuring it had been another uneventful day of filming, just another step in the learning process.

It wasn't until later that night, when I was carefully reviewing the footage frame by frame, that I saw them.
Three giant bluefin tunas—each likely over 90 inches based on the area's recent catches—had approached my low 30-inch class bluefish. 

They circled, investigated, and teased with their presence, all while I sat in the boat above completely unaware. These weren't just big fish; these were the monsters I'd been dreaming about filming since I was a kid. The same giants that Cape Cod commercial fishermen pursue during the peak September and October season.

Watching the footage, I could see they came close enough to study the bait. Close enough to consider it. Close enough that if I'd known they were there in real-time, my hands would have been shaking.

But they didn't commit. It was maddening and motivating all at once. But it was also a critical learning experience. 

Lesson Learned: Reviewing that footage carefully, I realized the slow trolled bluefish now looked much better with the bridle positioned on the eyes instead of behind the head. Nevertheless the tunas still refused to bite. I theorized they had seen the camera and been spooked by it.

Trip Three: When a Shortfin Mako Crashed the Party (September 14, 2023)

On this day I was slow-trolling a 30-inch bluefish in Cape Cod Bay without a hook, camera attached and moving at about 1.5 mph, when suddenly the rod jolted downward. Line peeled off the reel for a few seconds. When I retrieved the camera the bluefish was missing—something had struck from the depths. 

My heart pounded. Had I just captured the giant bluefin bite I'd been dreaming about since childhood? There was no way to know until I got home and popped the SD card into my computer.

The anticipation during that boat ride back was almost unbearable.

When I finally reviewed the footage at home, I felt a mix of emotions. Disappointment washed over me first—it wasn't a giant tuna. But then, as I watched the replay, shock and excitement took over. The strike was explosive—a shark had chomped down on my bluefish with incredible force. I was convinced I'd filmed a juvenile great white.

But Cape Cod waters hold surprises. Thanks to one of our My Fishing Cape Cod members who has a relationship with shark scientist Greg Skomal, he was able to enlist Greg's help in identifying this predator. According to Greg, this was a shortfin mako shark. Not what I was looking for, but incredible underwater footage nonetheless. The ocean had given me a preview of the power I was chasing—just from a different species.

Trip Four: The Shot That Changed Everything (October 5, 2023)

By October 5th, I'd put in nearly 100 hours chasing this dream. The Cape Cod tuna season was still going strong, but my belief that I would ever capture the shot was winding down. The water was cooling, and more importantly, my confidence was fading. This felt like it might be my last real chance to capture giant tuna bite footage underwater—not because the opportunity was disappearing, but because I wasn't sure I had it in me to keep trying.

It was 4:45pm and I was drifting at 1.5 mph with a 22-inch bluefish on 20-pound leader—no hook, just my underwater camera setup. The bluefish was nearly dead, the sun was setting over Cape Cod, and everything seemed stacked against me. In normal circumstances, I would have called it a trip.

Instead, I decided on one last drift.

Fifteen minutes into the drift, my sonar lit up with marks along the bottom. I dropped a jig to the bottom and immediately hooked into a big bluefish, which I promptly lost at the boat. I then watched on the sonar as an entire school of bluefish passed beneath by boat, holding tight to the bottom.

A massive "boomerang" mark then appeared on my sonar at 40 feet—the exact depth of my camera-rigged bluefish. This was unmistakably a giant bluefin tuna, and based on my sonar markings it looked there could be two others traveling along with it. I watched the screen in disbelief, thinking: "Are those giant tunas hunting bluefish right beneath my boat?"

Then the rod jolted downward.

Line peeled from my loosely set drag as a giant bluefin engulfed my bluefish. Not a tentative bite, not a taste-test, but a full commitment. I could only hope that my camera had captured it all in stunning detail.

When I got home and reviewed the underwater footage, I was speechless. Slowed down to 5% of actual speed, every detail was visible:

• The massive jaws opening with mechanical precision
• The bluefish disappearing in an instant
• The raw power of one of nature's most efficient predators
• A second giant tuna visible in the background, equally massive

Based on the size of the fish that had been recently caught in the same area, I believe this fish was likely a true monster—possibly as large as 800+ pounds. The bluefish appeared tiny in comparison, almost like a peanut next to this apex predator.

The ocean had finally revealed its secret to me. After hours of patience and persistence, I'd been granted the impossible shot—a giant bluefin tuna devouring a bluefish underwater, captured in a way perhaps no one had ever seen before.

The Takeaway

This underwater footage of a giant bluefin tuna devouring a bluefish represents more than just a cool video—it's a window into predator-prey behavior that few humans have ever witnessed from this perspective. It's a glimpse into the hidden world that exists just beneath the surface of Cape Cod waters, a world I feel incredibly fortunate to have documented.

I'm deeply grateful for those hours on the water—even the failed attempts, even the heartbreak of missed opportunities. Each trip was a lesson. The shortfin mako, the three cautious giants, the countless adjustments to my rigging—they were all necessary steps on the path to that one perfect moment on October 5th. This footage will forever remind me that Cape Cod waters still hold mysteries worth chasing, and that the ocean rewards those who approach her with patience, persistence, and respect.

As you plan for next season during these cold winter months, I encourage you to ask yourself: What's your impossible shot? Maybe it's finally landing that first tuna. Maybe it's simply getting your kids out on the boat more often and passing down your love of fishing. Whatever your goal is, ask yourself: What am I willing to sacrifice comfort for? What dream is worth the effort, worth the setbacks, worth the early mornings and late nights?

The giants will be out there. The stripers will return to the flats. The opportunities will present themselves. But the question isn't whether they exist—it's whether you're willing to put in the time, embrace the failures along the way, and trust that the ocean might just reward your persistence with something truly special.

Tight lines! 🎣

Ryan

A Note About the Comments Below:

When I originally documented this journey back in 2023, I shared each trip as a separate post on My Fishing Cape Cod. The comments from our community on those individual posts were incredibly insightful—filled with theories about tuna behavior, rigging suggestions, and encouragement that kept me going. Rather than lose all that valuable discussion, I've consolidated the comments from all four trip reports and included them below. You'll notice references to specific videos and details from each attempt—that's because readers were following along in real-time as the story unfolded. Their observations and feedback actually helped me refine my approach, and I'm grateful for this community's role in helping me finally capture the impossible shot!