the hat is about 20 inches wide (so normally you'd need 3X20 (or 60 inches) min.
but it has a ruffle (which is at least double (from a quick glance at cast on number 3 times!) as wide as hat.. or 60 inches X3=180 inches for tail!
1 yard/meter is 36inches/40 meters
2 yards/meters 72/80
3 yards 108/120
4 yards 144/160
5 yards 180/200--so 5+ a bit yards (or 5 meters)
truthfully... though with thick yarn.. its hard to plan.
i would use a 2 ball long tail cast on method.
[color=darkblue]tie 2 strands (each from 1 ball together (leave 6 inch or so tail)) together into slip knot.
make cast on using 1 ball for thumb, the other for index finger.
DO NOT COUNT SLIP KNOT AS A STITCH.
remove from needle before joining.
cut thumb thread after you have finished casting on. continue to knit with index yarn. (weave in extra tail with finishing.)[/color]