Paraman, you're right about using a mat. Mea culpa, but it wasn't obligatory where we fished (and to be honest I hate going out with anything but the absolute minmum of necessary tackle.)
Your obs about the effectiveness of surface fishing for carp is spot on, IMO. When fly rodding I've usually done at least as well as other guys fishing with baits nailed to the floor. I actually think that carp might be happier as surface feeders (subject to weather considerations) than as bottom feeders. Floating baits are very effective (NB floating trout pellets work just like dog bikkies, and when the fishery where the film was made temporarily banned dog biscuits, I simply switched to pellets, getting round an ill-thought-out rule aimed at surface baits).