For travel in 2026, you generally do not need a passport to take a ferry from the UK mainland to the Isle of Wight, as it is a domestic journey within the United Kingdom. However, ferry operators like Wightlink and Red Funnel strongly recommend carrying a valid form of photographic ID, such as a driving license or citizen card. While you may not be "checked" at a border control point like an international flight, having ID is often a requirement for the verification of your booking, especially if you are using discounted resident fares, senior tickets, or student rates. Additionally, if there is a security incident or a need for emergency manifests, having a photo ID makes the process significantly smoother. If you are a foot passenger without a pre-booked ticket, you can often board without showing ID at all, but for vehicle drivers, the booking reference and a matching ID are standard requirements to prevent ticket fraud and ensure maritime safety protocols are followed.