Is roaming free in Martinique with my European (EU) SIM card?

It is complicated. Since Martinique is a French Overseas Department, technically "Roam Like at Home" applies for EU citizens. However, many European carriers enforce strict "Fair Use Policies" (data caps) for overseas territories or throttle speeds. For travelers from the USA, Canada, or UK, roaming fees are extremely high as it is treated as an international zone. A Ti Porto in Viaggio Martinique eSIM guarantees a dedicated high-speed data allowance without worrying about carrier limits or bill shock.