Check before you go: elephanta.co.in/ferry-to-elephanta Ferry timings to Elephanta: The first boat leaves from the Gateway of India for Elephanta at 9 am. The last boat leaves for elephanta leaves at 3.30 pm.
Every 30 minutes or so a boat leaves for Elephanta. Also note, Elephanta Caves & ferry service to Elephanta island is closed on Mondays.