The eastern horizon beyond Block Canyon was just turning light blue, signaling the end of night. The adrenaline rush of the last fish had subsided, and I realized how tired I was. Sitting at the chunk board where we cut bait for tuna, I had drifted off when the sound of line burning off the Shimano 50 pierced my rest.

Mark leapt up.

“You want a big fish?” he asked with urgency in his voice. “This is you.”

“OK,” I answered, fully awake now. I strapped on the fighting belt and seated the rod. Line was flying off the reel.

This is what I signed up for when Mark dropped by my booth at a Las Vegas art show last summer. He liked my paintings of pelagic game fish and invited me to Montauk, New York, to fish Block Canyon’s Tails for yellowfin and bigeye tuna on his 35-foot Contender. Fast forward several months, and here I was, about 90 miles offshore and hooked up to my first bigeye, an experience I am unlikely to forget.

With the harness adjusted, I leaned back to lift the rod and take the load off my left forearm. I pumped and cranked like a madman, and in a few minutes Leif, the mate, shouted, “Got color!”

Already? I kept cranking. I caught a glimpse of an undulating turquoise silhouette well beneath the surface — and then, like a train, it charged into the deep. “It saw the boat,” Leif said. Indeed.

“Nick, we think this may be the fish,” Mark said. And then he added, prophetically, “This is going to take a while.”

He and Leif sat down as I began a tug of war with my first bigeye, the toughest fish, pound for pound, that I am likely to hook in my life. An hour went by. Pump, crank, pump, crank. With my knees braced on the padded gunwales, I balanced the work of my forearm and lower back by alternating muscles to pump the rod back up.

The sun rose, and the morning light glistened on the water. I was into the second hour, and it didn’t feel like I was gaining ground.

“You need some water?” Mark asked.

“Yes, please.”

“On your head?”

“Yes.”

I was surprised by and unprepared for the fish’s power and doggedness. I’d take 10 yards of line; he’d grab 50.

“Damn,” I said. “You have to be a man to fight a fish like this.”

“That’s right. Now be a man and get this damn fish in the boat!” Leif barked. “Go, go, go!”

After two hours, my body was breaking. I was not used to using these muscles. My lower back, left forearm, right shoulder and knees were cramping. I was engulfed in pain. I would reel and lift hard for a few cycles and quickly become winded. I was surprised. I consider myself to be in good shape. I’m 43, and I coach high school wrestling, a sport that I’ve done most of my life. I’m 5 feet, 9 inches tall and weigh about 205 pounds. I can wrestle back-to-back high school athletes and give them a run for their money. But this fish would simply not quit.

For what it was worth, the tuna struggled, too. It would burn off some line, then rest and give me a chance to win some back. We were using 50-pound class outfits with 50-pound mono and 80-pound fluorocarbon leaders. I was fishing about 17 pounds of drag. Although giving up never crossed my mind, I began to wonder whether my body would hold up. Mark and Leif coached me and cheered me on. They pushed me to muscle up the fish, but I couldn’t. As a wrestler, I could always tap some hidden reserve, even when I was exhausted. Not now. I just kept my eyes on the horizon and thought, Slow and steady wins the race. I pumped and cranked as time crawled on.

Three hours passed, and I was bathed in sweat. The back of my head tingled. My body was beyond fatigue. How many times had I reeled in to the rubber band securing the balloon? Five? More?

Each time my hopes soared I cranked harder, the fish sounded, and a half hour’s work was lost.

The tuna seemed indomitable; it was almost as if I were hooked to a machine. What genetic makeup gave him this unwavering instinct to survive? By now I wanted to call it a draw, but that isn’t how this game is played. I was fighting for my self-respect and the acceptance of my shipmates. I couldn’t give up the rod. That would be a disgrace. So I put my head down and kept at it.

Three and a half hours. My mind said go, but my body could not. I leaned forward and rested the rod on the gunwale. I couldn’t lift it. Mark sat by my side.

“His head is turning, Reel now,” he instructed. “Wait. Reel now. Wait. Now.”

Slowly, I gained a few inches at a time. The swells had gotten larger. One knocked me onto my back, but somehow the fish stayed on. I sat on the bait box. I couldn’t stand.

I had reached the breaking point.

“Can we increase the drag and give it one last shot?” I asked.

“We can’t. You’ll break him off,” Mark said.

“This is his fish,” Leif pointed out. “We’ll put it on full strike, and that’s it. If he breaks off, he breaks off.”

He pushed the drag up to close to 28 pounds, and I dug deep once more, pumping and cranking with reserves I thought had long been spent. The wrestler in me was back.

“We got color!” Mark announced. “Keep going. You got it. Go, go, go! You’re winning. Don’t give up. He’s tired. Keep it coming. I see him. He’s circling. Jesus Christ, what a fish! Here he is. I got the leader!”

First gaff, second gaff, third gaff. “Nick, we need your help getting it in the boat,” Mark said. “One, two, three.” All I could do was hold on and lean into it. With the tuna’s huge black head now on the gunwale, my hands slipped on the gaff, and I fell flat onto the deck. The 230-pound bigeye flopped down beside me. We lay next to each other, exhausted, in a pool of blood.

I collapsed onto a beanbag chair. As I lay there, my heart seemed to be palpitating. Am I having a heart attack, I wondered? If so, this is the way I’d like to go, I suppose, doing what I love. But is this still what I love?

It wasn’t my heart pounding. The bigeye was smashing its tail in the white fiberglass coffin box, fast and regular like a panicked heartbeat. I was dazed and confused, dehydrated and exhausted — and relieved.

It wasn’t me who was dying; it was the bigeye.