I've just had a short after-work session in the Cowfield swim. It really is an odd swim, it just screams fish yet it never really delivers the goods. I'm sure that I just haven't figured it out yet, but it's very frustrating. I fished it with my new favourite setup, trotting a very traditional looking crowquill avon with the 'pin. My casting with the pin is gradually improving, but is still abysmal. I've got used to trotting with it, though, and using it has become very comfortable. I managed a small chub of about a pound fishing hemp and caster, but no other bites were forthcoming.
I've got a feeling that, while it's fun to trot this swim, the presentation is all wrong. The pool drops away rapidly where the main river and the sidestream enter, and I've got a feeling that the flow and turbulence is very stratified. I suspect that in much of the first part of the trot, the water near the bottom is either very much slower than the current at the surface, still, or possibly even flowing backwards in a vertical eddy. The fish I've had on the float have either been from further downstream where the flow becomes more laminar and, I suspect, more consistent with a normal surface-to-bed velocity gradient, or else have come from the smooth eddy which feeds back into the confluence of the two flows.
Bearing this in mind, I think the correct way to fish this swim may well be with a large legered bait nailed to the bottom. I think that may have to be the next approach. Much less fun, though. I know a lovely glide not far from there, however, from which I've extracted a couple of very nice roach in the past, so that may need to provide my centrepin fix.