The Union Territory of Andaman and Nicobar Islands consisting of about 293 islands (39 of which are inhabited) is situated in the Bay of Bengal .

ENTRY FORMALITIES : 
Overseas Nationals: Foreign tourists need a special permit to visit the Andaman Islands . This can be obtained on arrival at Port Blair Airport .
Indians: Indian nationals need no special permits to visit Andamans. 

HOW TO GET THERE?
Air: Port Blair is connected by Indian Airlines, Jetairways and Air Deccan with Chennai, Kolkata and Delhi. This is the preferred way to reach Portblair.
Sea: Regular passenger ship services viz. M.V.Harshavardhana, M.V.Akbar and M.V.Nicobar are plying between Port Blair and Madras (1190 km), Calcutta (1255 kms), Vizag (1200 kms). This is not preferred mode of transport as it takes two days to reach Portblair.

From Portblair, Havelock Island is accessible by a Ferry and the timings are as under:

Port Blair - Havelock Ferry List - 

• Large - 6 AM Morning - 4 hours 30 minutes - 700 capacity - 3 classes (Bunk Class, Deck Class and Cabin Class)

• Small - 2 PM Afternoon - 2 hours 30 minutes - 94 capacity - 2 classes (Cabin Class and Standing)

• One more small ferry is added for 10 AM departure during High and Peak season

Havelock - Port Blair Ferry List - 

• Large - 2 PM Morning - 4 hours 30 minutes - 700 capacity - 3 classes (Bunk Class, Deck Class and Cabin Class)

• Small - 2:30 PM Afternoon - 2 hours 30 minutes - 94 capacity - 2 classes (Cabin Class and Standing)

• One more small ferry is added for 1 PM departure during High and Peak season

Fares - Rs. 200 for the Cabin Class. As the ferries have to be booked locally and dont have any computerised reservations system elsewhere where it can be booked, hotels / local agents reserve them for a service charge that varies from Rs. 100 - Rs. 150 per ticket.

Note: 

Hotels - There are limited rooms in Port Blair and Havelock and so prior reservation is an absolute must. The way ferries and flights timing mismatch, transit accommodation at Portblair at least once and in most cases twice is required.

Flight - Port Blair Airport is closed after 2 PM everyday. Therefore all Flights are scheduled during Morning to early Afternoon Hours. Flights are not co-ordinated with ferries for onward journeys and So all itineraries with Havelock Island have to be designed keeping 1 night at Portblair each way in Transit (As 2 PM Portblair - Havelock Ferry is small and so getting tickets is not always a certainty). Flights tend to go full during Season and to be booked well in advance.

Season

Peak Season - Winter - Dec and January (Best time)
High Season - Winter - Oct, Nov and Feb,March (Good time)
Summer Season - April-May (Hot and humid)
Low Season (Monsoon) - June to September (Unpredictable weather)