Louisa from the Hotel Barge ENCHANTE who cruises the canal du midi & the Provence/Camargue regions in the South of France enlightened us...
I've found most of our guests use their US phones and pay the fee. But it's quite easy to pick up a "pay as you go" phone (any big supermarket have them on offer plus there are lots of specialised phone shops) for about 35 euro which would include some credit. There's usually a deal going on one provider or another.This is a cool feature for Enchante that I didn't know about...
We've actually got a mobile phone for each of our cabins on Enchanté for their personal use while on board. When our guests arrive there's about 5 euro credit and they can top up anytime. The fees from a local provider are not half as bad as a US phone to phone the States.So, looks like it will be "pas de problème"