Plage de l'Espiguette: a fine beach. Go to the far end of the paying car park (8 euros a day last year) to be closer to the naturist part of the beach. The naturist part of the beach is clearly indicated, and in high season you can see from a distance the banner of Hélio-Club flying.
Palavas (known locally as Maguelone - I suppose this is the beach that you mean?): Go to the car park of Plage du Prévost (probably 4 or 5 euros), the naturist area is immediately to the west of the "Carré de Mer" restaurant. Quite a few textiles, but the naturist beach has so far been maintained.
Sérignan: the beach is just in front of the naturist camp site "Sérignan-Nature". I have no precise information about this beach, which I have not visited for probably over a decade; but it's there and used by people in the naturist camp site.
I do not know the other beaches that you maintain, apart from the baech at Vieillle-St-Girons in front of Arnaoutchot, which is typical of the naturist beaches on the French Atlantic coast. Fairly dangerous because of tidal streams, but with lifeguards watching.

Apologies for my spelling of Arnaoutchot in my original post. I guess my question is where can one park for public access to the naturist beach. It is probably 20 years since we visited Messanges beach, my recollection being that the naturist section of beack was between Messanges and the golf course at t Moliets. Thanks.

Serignan Plage is super, you can park within 300 metres of the beach in a car park alongside the holiday centre. We used it a couple of years ago and visited about three or four times during our holiday at Argen Minervois. Got there around 11 and fairly quiet car park and beach, some naturists come out from resort but not a huge number...nice family atmosphere. Most frustrating thing was the refreshment tent was 50 metres into the textile beach (clearly demarcated) so you have to slip on shorts for any snacks!
Recommend the beach!

Apologies for my spelling of Arnaoutchot in my original post. I guess my question is where can one park for public access to the naturist beach. It is probably 20 years since we visited Messanges beach, my recollection being that the naturist section of beack was between Messanges and the golf course at t Moliets. Thanks.

I've been to Messanges the last 2 years and you're right, but basically naturism is authorised out of the lifeguarded areas.
If you're ok with a short walk and climbing up and down the dune, look for le Domaine de la Prade between messanges and molliet, then follow the dirt road up to a small parking area in the forest, then follow the footpaths up the the beach. You won't find many people there and naturism is very common.

If you want to go to arnaoutchout look for a beach called la lette blanche North of moliet, then as far as I know you've got to walk 1km from that beach to arna's one.

We're off to France for 17 days in June and July. It's been a few years since we've been to thr locations we're proposing to visit. I'm therefore looking for views on the suitability of the naturist beaches at:
l'Espiguette and Palavas near Montpellier
Serignan, Toreilles, Bocal duTech near Perpignan and
Messanges, Moliets and near Arnachout (not staying on site) on Landes Coast.

Thanks in anticipation.

As far as Arna is concerned, in my experience the entire beach from the Gironde to the Spanish border is effectively clothing-optional except for the bits in towns, although there are a few brown signs scattered around pointing to "Plage Naturiste."