One of the most reliable early season hatches, or so I'm told. On Yorkshire's R. Wharfe it has started on or around the 22nd April for years. But I've never hit it. I've tried and tried, only to be told "You should have been on this or that length, if you had been you would have had a great day". Or the classic, "You should have been here yesterday".
Simple and elegant patterns Hans, love them, and will tie and carry some. But not with confidence that I'll get to use them!