Yorkshire Wet - Soft Hackle. The Yorkshire Wet Fly is a deadly trout and grayling pattern, and is not a new comer to the fish fishing community. This pattern has been tested like all other Soft Hackle flies and has demonstrated time and again that it is a serious contender as far as trout flies go. The Yorkshire Wet Fly can be used on lakes, rivers, ponds, creeks realistically anywhere with flat stretches that the Yorkshire can slowly drift by the waiting trout.