Recommendations for a nice spot on the Atlantic near Bordeaux?

These sites may give you some information

http://www.french-culture-adventures.com/france-beaches.html

http://www.francethisway.com/tourism/beaches-atlantic.php

West of Arcachon, across the bay, is Cap Ferret. It's on a narrow peninsula: one side with Atlantic beaches, the other side facing the picturesque bay. There are accommodations in the villages on this peninsula. I've stayed there twice.

South of Arcachon is the largest sand dune in Europe, the Dune du Pilat: well worth the hike through the pine forest, and descent to the oceans edge. You can also take a small boat out to the sand bar, Banc d'Arguin.

Plenty of good restaurants in the area, too.

LaRochelle is charming, close to the Carmague and, a placebwhere many Parisens vacation.

The Camargue is NOT near La Rochelle. It’s on the Mediterranean west of Marseille. Black bulls, white horses, pink flamingos. But I would recommend La Rochelle.

But also La Rochelle is north of Bordeaux, not on the way to it from Toulouse, so not really what the OP was after!

Have a look at Bidart. It's south of Bayonne and we stayed at a Logis de France hotel there once, which was steps away from an almost deserted stretch of sandy beach. Sorry not to be able to remember the hotel name.

I looked at Cap Ferrat and what I read made it sound more upscale than I typically prefer.

Bayonne and Biarritz are further south that I'm looking (I've visited beaches on the Spanish side of Basque country).

La Rochelle is something on my list for the future but further north than I want to go this trip. I might change and go further north before heading back to Paris but that depends on how my itinerary shapes up when I start taking items on my list and tentatively fit them into days.

Right now I'm thinking about the area between Soulac and Hourtin.