Does the bus from SP stop at the ferry terminal? And as a foot passenger arriving the day after carnaval should I expect a long wait to board the ferry?
yes, tell the driver that you want to get off at São Sebastião ferry ("Balsa") terminal to Ilhabela - and NOT at the Rodoviaria (bus station).
Many thanks. Can I buy a bus ticket on the day?
it is usually not a problem.
and you can monitor seat availability thru this website: