Targeting large game fish in deep water on fly was considered an impossibility before the 1950s, and even up until the past 15 years or so only an elite handful of fly fishers pursued it. Few people believed fly tackle stood much chance against billfish and other wide-shouldered predators, with even dolphin and tuna considered monster opponents for fly fishers.
In addition, most blue-water veterans considered it tough enough to get a boat within viewing distance of a marlin or sailfish, let alone get within fly-casting range. Another obstacle to accepting such an unlikely style: ignorance. Most offshore captains just weren't familiar with the rudiments of fly fishing and therefore tended to discourage it. Skippers complained that when a fish finally ate a fly, the battle consumed too much time and usually resulted in a break-off anyway.
The first problem -- fly gear that couldn't handle big fish -- proved to be more psychological than real. Fly fishers took more than casual notice of the successful techniques by light-tackle saltwater anglers of the time who had started to whip tarpon exceeding 100 pounds with some regularity. And if a 125-pound tarpon can be bested on 12-pound-test spin tackle, then why not on 12-pound fly tippet? For that matter, if it can be done on tarpon, why not sailfish, marlin and even bigger game fish?
The second challenge - getting the boat within casting distance of typically skittish billfish - seemed a tough nut to crack. But that too changed quickly as more sophisticated techniques using teasers to attract billfish, and fly anglers took note.
As surveys of the angling public revealed that the average fly fishers occupy upper-income brackets -- sacre bleu! -- the industry quickly recognized that most of those so-called "snobbish" folks could afford custom rods and reels and weren't the tiniest bit shy about laying out the big bucks for exotic fishing trips and weekend resort seminars. The result: a growing legion of long-rod aficionados who've become more and more adept at catching billfish and other species on fly.