La Rochelle, capital of Charente-Maritime and one of the most livable cities in France, is a pretty good place to go and get nautical.
If you want action, why not take to the waves on a catamaran?
Or if you'd rather keep your feet on the ground, you could go for a wander around La Ville Blanche (as La Rochelle is known) and get some great views by climbing the two towers that used to protect the harbour from the troublesome English.
A highlight is visiting La Tour de la Lanterne, which has acted as a lighthouse and a prison and has graffiti made by forlorn English prisoners in the 18th century and a backgammon board carved into the floor by someone in room 4.
To see what is going on under the surface, you could visit the aquarium and while in a sea mood, check out the maritime museum, before heading to town's long sandy beach.
When it comes to food, well it's seafood obvs, but leave some room for these other specialities.
But this is also a place to discover the part this département plays in the French love for parenthesising meals with aperitifs and digestifs. The not so well known local aperitif, Pineau des Charentes made from fortified grape must, is a pretty good prelude to any meal and world-famous Cognac is a perfect end. There a many places to try these local tipples, but this one is just by the harbour.
If you have a day or two spare, why not visit the Île de Ré? You can take a bus or boat there and use the RespiRé electric shuttle bus or hire a bike and cycle around the island exploring the 10 villages and trying oysters from the cabins
Highlights
Stroll around the old harbour and towers
Bookend a slap up seafood feast with pineau des Charentes and cognac
Visit the Île de Ré
Station stroll ideas
If you have an hour or two to spare waiting for a train, why not go for a wander?
Tourist info provide a set of maps and brochures here.
I've also made a downloadable PDF with accompanying google map which will give you a feel for the place and take in the sights.
Guided tours
Tourist info provide details of a couple of guided walks here
Luggage
If you want to stroll without a care in the world, including your luggage, you could try using Bounce to find a place that will take your bags.
Getting there
It takes around 3 hours from Paris and 2 hours 20 mins from Bordeaux.
Useful links
La Rochelle tourist info: https://www.larochelle-tourisme.com
Île de Ré tourist info: https://www.holidays-iledere.co.uk/
Where next?
How about Bordeaux?