Estimating weight of cleaned fish

I've been told that you normally get 60 percent of a blue marlin's weight in flesh...

Q: On June 26, 2007 I caught a nice black marlin and boated the fish to have it weighed. Unfortunately, when we hung the fish back at the dock, the fish broke the scale. I didn't get any measurements, but after it was cleaned, the flesh weighed 444 pounds. We see a lot of blues in the same size range as this fish, but this is the first black that I ever caught, and I have no experience with estimating their weights. I've been told that you normally get 60 percent of a blue marlin's weight in flesh when you clean them? Is this a true estimate?

Dominque De Baize,
Mauritius

A: I'm sorry, Dominque, but I have no experience with this type of estimate.

If you could have provided the lower-jaw-to-fork length and a girth measurement at the fish's widest point, I could have worked it out pretty closely for you. There's nothing I can really tell with just a partial flesh weight, other than the fish probably weighed well over 500 pounds ­ possibly 600.