I am always uncomfortable when someone sends me a photograph of a marlin that they released or lost and asks me to estimate the size of the fish. The best answer I can give, especially if the fish is jumping far off in the distance, is always "I can't really tell much from a photo." You see, a short, fat 500-pound marlin is shaped very much like a short, fat 1,200-pound marlin, and even if I had actually been on the boat, saw the fish jump and had a rough idea of how far away the fish was, I could only be completely sure that a 500-pound fish is a medium and a 1,200-pounder looks like a large. New auto-focus cameras with laser range finders might some day be able to give us a fairly accurate length and breadth of the fish, but even direct measurements of a dead fish are not enough for an accurate weight.
The fish that really fool me, and usually every one else on board, are the long, skinny ones with great big heads. I vividly remember two such fish. Both were black marlin that we estimated at more than 1,500 pounds during the fight. Both fish crashed big dead baits, and the distance from the dorsal fin to the tail looked immense. The baits that the fish ate, one a scaly mackerel and the other a small tuna, both weighed close to 20 pounds, and the marlin slurped the baits down in an instant. An impressive sight to say the least!
One immediately jumped, open-mouthed, toward the boat, and the other did a half jump, shaking its giant head. Their great lengths and huge heads convinced everyone on the boat that we had a new world record on the line — if we could just manage to catch them.
We only got to see the real shape of the fish when they came alongside the boat. One weighed a little more than 1,100 pounds, and the other just barely hit 1,000. Both were nice, big marlin but not the record-size fish we expected during the long, hard fights. They both tapered off behind the shoulders, with skinny dimensions behind the midsection.
The charts some agencies pass out based on length and weight ratios are wildly inaccurate. Charts with both weight and girth are somewhat more accurate but remain, at best, inexact. When I was in high school, I was 5 feet, 10 1/2 inches tall with a 32-inch waist and weighed 145 pounds. The famous NFL fullback Jim Brown had the same measurements but weighed 235 pounds. I never learned his chest and thigh measurements, but I'm sure they would have dwarfed mine. Using length and a single girth to estimate fish weights can also have disparate results.
A Record-Size Marlin
On the other side of the estimating experience, my entire crew and I hugely underestimated the biggest marlin we ever boated. When the 1,442-pound fish, still the Australian record, jumped at about 200 yards out, we all called it 800 pounds. Even after a series of nice jumps, less than 30 feet from the boat on the leader, I told the angler, Mick McGrath, it was certainly more than 900 pounds but that I couldn't be sure it would break the magic 1,000-pound mark. In retrospect, I realize that the fish was just so fat that it did not appear to be as long as it really was!
When we finally gaffed it, I immediately told Mick it would definitely go more than a grand. As we tried to get it into the boat, I upped the ante to 1,200 pounds. Even when we stalled the anchor windlass pulling her through the transom door, I still didn't realize the immense size of the fish.
Only when I actually put the tape measure on the fish did we realize that she was long, fat and really big. Her maximum girth was 7 feet, 3 inches, and her short length was 12 feet, 7 inches. Ten days earlier, Garrick Agnew's boat Pannawonica boated a 1,417-pounder that had a 12-foot, 1-inch short length and a 6-foot, 11-inch girth. Ours measured much bigger, and we thought it might beat the old record of 1,560 from Cabo Blanco, which was 14 feet, 6 inches in total length (probably between 11 feet, 6 inches and 12 feet, 2 inches short length) with a girth of 6 feet, 9 inches.
A 20-Inch Tail
Many top marlin crews know to take another measurement on big blue and black marlin to try to ascertain whether the fish will or will not make it as a grander. If the thinnest part of the butt of a marlin's tail measures more than 20 inches, it will almost certainly exceed 1,000 pounds. I have only seen a couple of very short, very fat fish not make 1,000 pounds if they had a 20-inch tail, and they were very close, in the high 900s. In today's world, those fish would be released at 1,100 pounds.
It all started in Cairns in the late 1960s with a man named Dick Fitzhardinge, who was weighmaster of the newly created Cairns Game Fishing Club.
After having a couple of monster fish crash down from the gantry when a looped tail rope pinched their tails off, Dick started using a piece of chain as a tail rope and deducting the 10-pound weight of chain from the scale weight.
Dick had to go down a set of steps (Cairns tides vary up to 10 feet) to reach the water and attach the chain to the fish. As he was attaching the chain, every once and while Dick would say, "This one will make it," and he was always right. After several of these pronouncements, my curiosity got the better of me, and I asked him how he knew when a fish was more than a grand before it hit the scale.
"If I can't get both my hands around the tail with my thumbs and middle fingers touching, I know it will go," he said. (He made his "measurement" right at the base of the tail.) And Dick was a big man with big hands.
Since my hands were much smaller, I grabbed a tape measure, measured Dick's hands, and the 20-inch-tail rule was born! I have seen many fish with a girth of more than 6 feet and much more than an 11-foot short length with as little as 18 1/2-inch tails make it to 1,000 but only a couple of fish with 20-inch tails that did not. (One was 988, which was close, but no cigar.)
