Metropolises close to water need sustainable mobility solutions. Two student teams developed autonomous, fully electric ferry concepts that reduce car traffic and promote climate-neutral local transport. The ferries are ‘ultra simple’, cost-sensitive and rely on minimalist designs that can be realised immediately. These concepts not only offer the attractive service of the crossing, but also integrate autonomous systems to counteract the shortage of skilled labour. They serve as a reference for global innovations in autonomous mobility on water.