Aye Andrew,3 indispensible Harray flies there,Merky Maid, Peach Muddler and Doobry Muddler. My first line of attack in a caenis hatch are suspender buzzers,claret or hares ear,dont be fooled by rising fish and putting "dries" on,they rarely take the surface flies,but gorge on the nymph,can be fantastic sport with pods of fish coming at you,look out for the "slicks" and calm lanes,that's where you will find them,
Cheers KEN