Le Porge is one off the closest beach to Bordeaux (55km). The landscape is the same you can find on all the Gironde Beaches. That means sand dunes for miles and miles. On average days, Le Porge offers mellow waves.
On bad days (strong north wind or west wind), there is not much to try and do. Short bumpy, choppy waves. On good days, you can find some close to perfect beach break waves. 100 to 150m, sometimes 200m long rides are possible with hollow waves (not as hollow as Hossegor's anyway). The perfect size is betwin 1m20 to 1m50 (4 to 5 feet). Under that size, it can be great too, whenever it's powerful, but a longboard can be a good idea (riding a 2 to 3 feet wave on 100m is so much fun). Over 2m (7 feet) the chances to have a good surf decreases very fast... Because it becomes hard to join the line up. One main aspect of Le Porge (and other places in Gironde) is the distance you need to paddle out to go to the line up. The sand bars can be far from the shore as the bottom's slope is quite flat (that allows waves to be ridable so long). You'll need to be a good paddler to enjoy sometimes. The only problems you could find in Gironde are the strong rips: "courrants de Baïnes". They happen mostly on low tides but are very predictable.