The Indian government has been advocating eco-friendly tourism development on Havelock for a while now, and while it's the most visited of the islands it sees only a fraction of the visitors that crowd other island destinations such as Thailand. The pace of life is slow, the locals are friendly and still not too affected by tourism, and the facilities are moderately basic for the most part. While many of the lodges have 'resort' in their names, none come even close, thankfully.
The beaches have been given a rather boring numbering system instead of names, although some names like Radhanagar are in popular use. The arrival port is at Beach #1, the junction at the center is Beach #3 (aka Govind Nagar), the junction near Dolphin Resort is Beach #5 (Vijay Nagar) and so on. Govind Nagar, the main "town", is small and has only a handful of shops and local dhabas. Most accommodation is grouped along the road from Beach #3 to Beach #5. From the 'junction' near Beach #3 a road veers off to Beach #7 (Radhanagar Beach), the most beautiful spot on the island.
Mid-January until mid-May sees the best weather, and often the best diving conditions. The days are mostly sunny at this time of year, and the sea sometimes flat enough to reflect the clouds. The monsoon usually hits around late May, lasting until the end of July, and is probably the worst time to visit the island – strong winds, frequent rain and low visibility underwater. August thru November see some occasional showers and slightly rougher seas, but diving can still be great at this time of year. The weather often takes a turn for the worse for the month of December through early January.
Havelock island now has two ATMs; SBI and Axis bank. Some of the hotels and resorts are able to perform card transactions. Nevertheless, it is best to make sure you take plenty of cash with you from Port Blair. Also, it is hard to buy some items in the market - differing factors of sun cream can be hard to find, as can mosquito repellent.