good and cheap option in case you don’t have a boat is to rent
one at the Santa Luzia Dock. There are price charts to several
points at the Long Island. Depending on how many people you have
on your party it can be very cheap. You can rent a boat to take
you to the islands and come back at the end of the day to pick you
up or it can stay with you the entire day.
option is the BARCAS S/A (EX - CONERJ) ferry (see at Ilha Grande).
It makes the journey Angra-Abraão (Ilha Grande)- Angra everyday).
below some pictures and pricing.