Try dive vs Open Water: what is the difference?

A try dive is right if you want a first dive without committing to a full course. You remain under instructor supervision and are not an independent diver afterwards. Open Water is a multi-day path (duration is on the course page) covering skills to dive with a buddy within the issued certificate limits. A training card is not automatically a government licence. If an authority needs a specific document, ask the centre before you enrol.