Public Swimming Pools in Paris

This may be the closest to you, not too far. I seem to recall that showers before swimming are de rigueur.

http://www.timeout.com/paris/en/sport-and-fitness/piscine-pontoise-quartier-latin

Here's the whole list:

http://piscine.equipement.paris.fr/tousleshoraires

Our one experience with public pools in France was in Chamonix. Speedos were indeed required for men and boys--no baggies or board shorts. And caps and shower shoes. And showers before entering the pool. This is all good, as they help keep the pool clean.

Make sure you understand the hours for different types of swim---lap swim ( lanes set up) versus free swim ( no lanes).

There is the summertime Josephine Baker pool on the river Seine. Google for photos, info and location. Looks like fun.

You might have been reading about Speedos and swim caps in Rick's Paris book; he does say that on p. 497 in the "with Children" chapter.

You've probably figured this out by now: this is going to be a different experience than having a swim here.
Most people here don't do this in Paris. So, should be interesting: let us know what you thought, after doing it.

I totally concur with suggestion of the Joesephine Baker swimming pool for kids. Yes , swim caps and speedo type suits needed however ( which my sons would have never agreed to unless very young) . If children are young (under 8-9) they may enjoy an afternoon at Paris Plage. No swimming pool that I recall, but a beach set up along the Seine , with sand, beach toys, and water sprinklers for kids to run through and under. Concession, ( selling basic snacks, need , hard cider, and ice cream) . many local families picnicing. Usually runs mid July through mid august.

Another answer to the Speedo challenge: Swim naked. Three evenings a week a "naturiste" organization operates at Piscine Roger Le Gall in the 12th. http://www.naturistes-paris.org/spip.php?page=backend And no, it's not sexy, since a swim cap is still required. Children are admitted with parents; the French regard naturism as a family affair.

Your kids my get a kick out of the Joesephine Baker Pool, it's set up on a barge, anchored, out on
the Seine.