Two carp a clooping

The other day while smallmouth fishing I noticed a strong hatch of mayflies coming off. Hoping this was a several day event I was back on the river this evening with flyrod in hand after some carp. Traveling somewhat backwards in the year I headed towards a spot I fish as a wintering hole for smallies. The hole has a big very slowly revolving eddy that kinda traps all the detritus floating down the river. Sure enough there were a few carp in there clooping gunk and bugs off the surface every now and then. Wow they were spooky, the first cast put down every fish for ten minutes. Time I used to add about two feet to my leader. My fly was a very small white marabou muddler unweighted with most of the leader but not the fly treated with floatant so it just sort of hung right at the surface looking I guess like another clump of gunk. I only managed to land a couple fish but had an interesting, kinda frustrating but fun trip doing things a bit differently tonight.