Seapilot Navigation App uses vectorized S-57 chart data from national maritime administrations. The chart presentation is based on professional standards for ECDIS (Electronic Chart Display and Information System).
Nautical charts are purchased by country and include charts for all coastal areas and – for some countries – major lakes and waterways as well. Some charts are free of charge (most US charts for instance). Those are stated as Purchased in your account settings – please note that it doesn’t mean that you’ve actually purchased and paid for them.