There's an 'related stories' link down the bottom of the page with a bit more info. The ferry has a runtime of 90 minutes, and the regular trip takes "just over an hour", and a full recharge takes 60-90 minutes, with chargers at both terminals. So a return trip would take 2 hours + 2 charges, so somewhere around 4 hours. So I'd estimate it could do ~6 return trips per day.