We have already explained here at the Brazil Travel Blog how to get from Rio to Angra dos Reis / Paraty and from São Paulo to Paraty. But anyone spending time in the region will, at one stage or another, need to get from Paraty to Angra dos Reis (boat to Ilha Grande) or viceversa. For that purpose, there is a different bus service.
As there are no guarantees the sites will be online in months and years to come, here’s a summary of the info. One of the pages shows a different schedule from Monday to Saturday; the other site states the schedules are the same from Monday to Sunday. In any case, there are 25 daily services from Paraty to Angra dos Reis and viceversa. The first one leaves at 05:00 and the last one at 22:30 (from both ends). One of the sites states that on Sundays there are only 18 services.
I haven’t been able to find out the price of the ticket. The trip takes about 1 hour.