The professional version is the way to go for commercial vessels and operations, professional seafarers, shipping and offshore companies. Offline USB for Windows, multiple downloads, updates and replacements, current medical documentation and our helpdesk are included, among other features. See chart below.
If you just want a personal copy on your mobile device and that's all you want, the personal version is your best choice. Online-access or a one-time download of the full version are yours to take anywhere you go, for the life of your device. No updates included. See chart below.