In the early days of marlin fishing slow trolling flying fish was the accepted method , Flyers have a enlarged backbone that helps them to create strength for thrust to escape their predators tunas or marlins. This strong backbone also serves in helping them to troll without breaking apart quickly. Trolling flyers can be as simply as put a hook through their lips and troll em' or sewn up keeping their wings tied down and a bridle or harness rig made to keep them from washing out premature.
Using a 3ft length of deno-tape or waxed dacron thread, insert through nose hole, back through body under the wing, then over the back and through the same hole again, in effect holding down the wings.
Pull the thread taught (leaving a 1ft. out) and go through the nose hole again, using needle, with one strand of the thread come down directly through and out the bottom jaw, with the other the strand, come up, cut a small notch in lips- tie the two strand together to form the harness
The eyes can be further crossed to prevent being washed out by using the needle and a second piece of thread, insert above the eye socket- exit other side, back thorough under the eye and tie off.
Hooks can be tied to the harness either tight to the lips or out an inch or so to prevent being fouled in the bait when it's eaten- Best of luck- JD
Giant Squid rigging