If you are going to get the best sport from a plaice, you will need to tackle it accordingly. Personally I like to use A really light rod and reel - a 6 ounce test curve baitcaster - which enables these obliging flatfish to put up a much more spirited performance than conventional rods and reels.
If you are going to fish for plaice from a boat, then the most obvious starting point is to take the boat to a place where the fish congregate. You will, for example, find plaice over sandy or gravel bottoms, such as areas a short distance out from productive beaches, but they will not be spaced evenly from one end of the beach to the other. Instead they will collect in particular spots where the food is abundant. Moor your boat directly over such marks and you can have a terrific day. Miss it, sometimes by just a few yards, and the numbers that turn up scarcely justify the effort and the cost of the fuel.
So what do you look for? You can use the echo sounder, if the boat is fitted with one, to chart the bottom, looking out for pits or places where the food may be abundant, but a better bet is to head for places, like sandbanks, near the mouths of estuaries or just around the coast from them, like the famous Skerries, which are fairly close to the River Dart. Once you get there you need to decide exactly how you are going to fish. Some people choose to anchor over a particular spot, but my own preference is to drift with a predator rig. This enables you to cover a lot more ground and, theoretically at least, gives you a good chance of finding where the fish are feeding.
You also need to decide what tackle to use. Personally, I like to use a light baitcasting rod, such as the Masterline six shooter, matched up with a light multiplier such as the Toothy Critter. Plaice will not, after all, give you a heroic battle on heavier gear, but a good one will put up an excellent fight on light spinning rods or outfits like these.
For the terminal rig I like to use a variation on the running leger which I have nicknamed the predator rig. This enables the bait to behave much more naturally than paternoster rigs and is far less likely to tangle. I would also say that it is a pretty simple rig, although I do like to end the trace with a wishbone, which I have found to be very, very productive.
The first part of the leger is very straightforward, with a bead, link swivel or sea leg on the line, to which a weight is attached, followed by a bead, a piece of carp tubing, perhaps 10 cms long to help avoid tangles, another bead and a swivel tied to the end of the line. The trace is then 3 to 4 metres long, to enable the bait a bit of movement, with a Breakaway swivel T on the end. This will be used to make the wishbone, which you will construct by taking a second piece of trace, 1 metre long, and threading it through the swivel T. Slide on a bead, a stop, perhaps made of coiled telephone wire, and then tie on a hook. (I use size 1/0 Aberdeens.) Do the same to the other side, but add several beads before you tie on the hook. Take the plain side and use the stop to secure it much closer to the swivel T than the beaded side, then use the second stop to trap the swivel T firmly in position.
The diagram on the next page should make the tackle clear, but the idea behind it is this. Over the years I have found that smaller plaice tend to be quicker to the bait, especially if there are beads to attract their attention. The result is that where there are numbers of smaller fish it becomes difficult to reach the bigger ones. This tackle, however, has something for everyone, so to speak. The smaller plaice go for the longer side with the beads, which leaves the bigger fish able to make a beeline for the plain side, which will have a very large bait on it.
As well as using standard leger rigs, you can also use baited spoons or smaller spoons as attractors. These tend to catch smaller fish than the predator rig, but it can make a difference on days when the fish are scarce, in which case it is better to catch smaller fish than no fish at all. If you fish them with beads, try matching the beads to the bait.