Using a phone card onboard

We are on the June 1 sailing of the Regatta . Does anyone know if it is possilbe to use a phone card to call from the ship. My husband may need to call home for business and to check on his mother. He has a company card. I could take my T-Mobile phone but the air time is expensive and I doubt that it would work from the ship . If anyone has had experience in this area, we'd appreciate your imput.

Thanks