In France carp fishing is in its infancy, but unlike the UK where it gradually evolved driven by experimentation and a few dedicated anglers putting the hours in, here they all use the same methods taken straight out of the French equivalent of Carp Monthly. That involves pods of four rods set at waist height with line you would use for shark fishing and the use of an inflatable boat to drop their groundbait and marker buoys
Much of this is done over 'le weekend' and involve night fishing. All over France on lakes and some rivers you will now see signs for 'Carpe de Nuit' meaning that you can night fish specifically for carp(e) in that area. You can't stray away from the designated areas and you have to restrict your choice of bait to whatever is on the local licence. Night anglers are regularly checked by government apointed Angling Police who happen to pack side arms and apparently aren't known for their tolerance to foreigners fishing without licences.
I've come across them when walking the dog around the lakes and once, on a Friday afternoon, I was fishing a swim where I don't usually venture when three car loads and one trailer load of fishing tackle descended into the area I was fishing. Three guys got out and started to scout the area and it became apparent that I was in the swim they wanted to fish. I had chosen it simply because the trees were high enough to allow me to use the 15 foot float rod. But it was also big enough for a four rod pod as were the swims either side. When they asked if I was fishing all night I said "No, but I'm not going home until dusk" their little faces dropped. Even though it was four hours from dusk they began to set up the rod pods and tackle behind me so they could get into my swim as soon as I left. One began blowing up the dinghy. I got chatting to them and it turned out that they were from out of the department and were intending fishing the whole weekend. The trailer was full of Friskies, the dog food they use to bait up with. I decided that being retired I could fish any day whereas they were looking forward to their weekend carp fishing so I packed my tackle away and let them take over the swim while I watched and chatted to them.
Their end tackle was crude to say the least. I'm no carp expert, but I'm light years ahead of these guys. Their catch rate wasn't much to write home about either.
The funny thing is, at the other end of the bay they were fishing, about 1 kilometre away, but not where they could park at the waterside or night fish, was a pod of several huge carp that were never fished for except by me.
One thing to mention about the Vienne is that it is very rocky in places. You might want to make sure you have some suitable line. you find carp all over the place in the river. Steadier flows seem to be the best spots, but there are weirs every kilometer or so and upstream of these are good holding spots.