If you are just happy going fishing, then the excitement of not knowing might be part of your enjoyment, but for the specimen hunter knowing the potential of your target venues is essential information.
Yet, this doesn't mean that you have to take the element of mystery out of your fishing. We never know everything there is to know about a fishery, so there is always some mystery involved. Even in heavily fished venues it is quite common for only half the fish to get caught on a regular basis. The other half might never get caught at all!
Many venues keep good records of the fish caught from their waters. Just have a look at WWW.RMCANGLING.CO.UK and you can get a good idea of the potential of each of their fisheries very easily. Other clubs and organisations could learn a lot from the fantastic information put out by RMC. With species like tench, often one or two individuals can become bloated with spawn. Miss-weighing does also happen and some fishery bosses are more fastidious about their records than others. More interesting to me are venues that regularly turn up larger than average specimens. Note these venues as given a couple more years they could produce something truly exceptional.
Another good source of information, and one that I use a lot, are the catch reports in the angling press. Again, you do occasionally have fish that are miss-weighed, although most of these are pretty obvious from the photographs. Very few fish seem to be deliberately reported at the wrong weights by the way. The most common problems are scales that revolve several times, leading to fish being recorded on the wrong revolution, and anglers forgetting to zero their scales to take into account the weigh sling. The odd hybrid also slips through, particularly of roach and rudd, but identification is generally pretty good. Unless they are very obviously wrong then the weeklies do provide a huge amount of useful information.
Although not every report will give exact details of the fisheries location you will still start to see patterns in catches and often the location will eventually emerge. It can pay to be a little careful though. More than once I have been caught out and joined the wrong venue when my 'guesstimates' have gone a little awry!
There are still a lot of big fish out there waiting to be discovered, particularly in rivers, but if you are interested in species other than carp then lakes can also produce some surprises! Whilst it is still a bit cold at the moment to look for fish, it is a good time to start making plans. Get hold of the local Ordnance Survey maps and mark on them the locations of any big fish waters that you know. I would begin my search at any venues close to these known hot-spots. Often it is surprising that even though adjoining venues share much of the same history only one will be in vogue with the local anglers. Big fish waters often form little clusters where conditions are just right so bear this in mind. It is also worth noting any venues that are difficult to access. One lake I fish requires a twenty minute walk and has a very dodgy car park, the former putting off most of the locals. Yet if it is big tench you want then this place takes some beating.
Although fish can move around much more in rivers, some areas still get left alone and can contain surprises. Just recently, a friend of mine tracked down some known big barbel that were spending much of the year several miles from their known haunts. Whilst other anglers fished the known haunts, this guy caught a stack of big fish by using his head. Again, look for those stretches that produce big fish. Are there other adjoining areas that are rarely fished?
When the weather does warm up a bit, normally around the beginning of May, have a walk around some of these potential venues. With the fish often in the margins and high in the water as they prepare to spawn, fish spotting opportunities are at their best. You can keep looking right through the Summer. Don't be put off if you don't see very much at first, often it can take a while to get your eye in and learn the location of the fish. Stick at it though and with a bit of effort you may just surprise yourself!