I went out there around mid may near the bottle depot and I had not so much as a touch on my line. (I was fishing a flavoured dough on the bottom)
It could be May was too early and the water needed to warm up some more - to be honest that was the first time I tried for Carp there. I figured I would wait until the weather warms up a bit and it's been slow doing that so I have not tried for carp again. I think I will try again in July / August when they are likely to be more active - cannot say how they are right now but I would love to find out (hint, hint).
Spey casting for carp? Hmmm...if that involves a fly..good luck. I have heard it can be done but it must be a realy challenge getting them that way.