Elephanta caves is some 10kms away from Mumbai.
There are regular launches leaving from Gate way of India. These launches do not ply during monsoon because of the bad weather and sea being rough at times. Also there is a guide available at Elephanta island who would give you all the information and tell you the historical importance of the caves. One can take the conducted tour which is organised by MTDC. When taking the guide one should be careful and take only authorised guides who are well trained by Tourist office, Govt. of India. Booking can be done directly from Gate of India or also from MTDC office at Barracks near Mantralya. There is also MTDC canteen on the island where you get all the foodstuff, Cold drinks etc. But it is better to take your own packed lunch since such kind of stuff is quite expensive on the island. This place is very famous amongst Mumbaiyites because of its close proximity to the city and easily available mode of transport. Last launch leaves from Gate of India at 4 pm in the evening. The whole trip takes about 5-6 hours but it is a nice place to spend a day if you are visiting the place in big group. IT is certainly worth a visit.