Here’s a step-by-step system that Captain Aldo Nava, www.niagarafishingadventures.com , uses to fillet eating-size trout & salmon for his guests.
The first thing is to have a proper, flexible fillet knife like the Rapala EZ Glide fillet knife.
Next, he starts by inserting the knife behind the head just to the vertibrae and rib cage.
From there he makes a smooth cut to separate the fillet form the body right to the tail.
When both fillets are removed he carefully uses the flex of the fillet knife and gently removes the rib cage.
Lastly he trims the belly fat. This removes any contaminants that may have been deposited in the fatty-tissue and also makes for less fatty, better tasting fish, no matter how you prepare it.
The boneless and fat-less fillets are rinsed off, allowed to slightly dry, bagged and kept on ice until the angler gets home. Aldo leaves the skin on so the fish can be easily identified and leaves the fillet whole so it’s easy to guess the size of the fish!