Your Crew Card is your identity inside SeaLog — the same record your rotation, your dashboard, and (if you're on a managed vessel) your admin's roster all read from.
If you're not tied to a managed vessel, create your own card from the Home screen — name, rank, department, photo, and a few personal fields (passport, next of kin, and so on). If your admin has issued you a QR Crew Card instead, scan it from Settings → My Crew Card to link your device to their vessel.
Beyond the basics, your card carries your rank, department, certificate of competency and passport numbers, nationality, date of birth, and a next-of-kin contact — enough that a "My Dashboard" ID & Emergency drawer can actually be useful in a real emergency, not just a name and a photo.
Once your join date and work/leave schedule are set — by you on a solo card, or by your admin if you're on a managed vessel — your Home screen shows your current onboard/off status and a countdown to your next change automatically. Nobody has to work it out by hand.
If you rotate with a named partner (a "back-to-back"), linking the two crew cards means a change to one schedule is reflected in the other's handover date — instead of two separate spreadsheet rows that quietly drift apart.
Next: see Logging Work / Rest Hours.