I'd say that what Rob has outlined is also applicable to small Southern clearwater fisheries that get very hard fished, and K should definitely factor fishing pressure into his thinking. This comment based on experience a few years back of Chalk Springs at Arundel. Mondays were a hopeless day to fish because the fishery had been hammered at the weekend, and the "Chalk Springs weekend" includes Fridays as well. Tuesdays could be a little better. Wednesdays were sometimes fished by clubs and societies on organised outings. Depending on how serious the Wednesday fishing pressure was, and those club days may be quite easy-going, Thursday could be a good day to fish. Then rinse and repeat..... I no longer fish Chalk Springs for several reasons, of which the above is just one. B*gg*r of a 40 mile plus journey along the A27, I did not particularly like the almost suburban setting on the outskirts of the town, and more interesting fishing available in Hampshire and Wiltshire being the others.