I'm about three months late with this reply but in case anyone else needs a recommendation for La Rochelle I've stayed three times at Hotel Les Brises (
www.hotellesbrises.com), and it was perfect. It's about a 5/10 minute walk from the centre of the town, it's on the sea, book a room with a sea view and you get a balcony with a stunning view. There's no restaurant in the hotel (cold breakfast only), but there are dozens just up the road. It's quite basic, but has everything you'd want and is ultra clean.There are other hotels in the town, raging from luxurious to bog standard, but the town can be very noisy and busy at night, so beware.