The "yachtie" is clear about not being able to get the tourist visa on arrival. India does not offer VOA....
You must have a valid Indian visa, and apply for a permit to visit in advance. Yachts that have arrived without visas will only be permitted a 3 day stay. Indian visas can be obtained from Indian Embassies in Singapore, Kuala Lumpur, or Bangkok. Visas are obtainable in Phuket from Emotion Travel for a fee of 3000 baht each and it takes 10 days to obtain (Emotion Travel, 104 Rasada Road, Muang, and Phuket). These visas are generally for 6 months and apply to the whole of India. The embassy MUST endorse BY HAND the visa stamp in the passport with the following words: "Visa also valid for visit to permitted places in Andaman and Nicobar Islands for tourism only." If this is not endorsed then they will not let you in. The yacht's name on the endorsement may also be an advantage.
ENTRY FORMALITIES FOR FOREIGNERS AND INDIANS
All foreign nationals can stay in the islands for 30 days. This can be extended by another 15 days with permission. They require a permit to stay from the immigration authorities. In addition, permits can also be obtained from: Indian Missions Overseas, Foreigner’s Registration Offices at Delhi, Mumbai, Chennai, Calcutta and the immigration authorities at the airports at Delhi, Mumbai, Calcutta and Chennai.
The places covered by this permit for night halt are: South Andaman Island, Middle Andaman Island and Little Andaman Island (except tribal reserve), Neil Island, Havelock Island, Long Island, Diglipur, Baratang, North Passage and islands in the Mahatma Gandhi Marine National Park (excluding islands – Boat Hobday, Twin, Tarmugli, Malay and Pluto) Night halt in the Park is with permission only.