The festival of Nariyal Purnima or Narali Purnima is largely celebrated in the regions of Maharashtra. It is observed on the Shravan Purnima or the full-moon day in the month of Shravan—this year falling on August 18, which also happens to be Raksha Bandhan.
Narali Purnima Timings and Tithi are as follows:
Purnima Tithi starts = 16:27 on 17/Aug/2016
Purnima Tithi ends = 14:56 on 18/Aug/2016
(The Tithi timings have been taken from Drikpanchang.com)
In Maharashtra, the day is celebrated with much fervour and zest, especially along the coastal and Konkani regions. On this day, God Varuna, who is believed to be the protector of the Sea is worshipped. Both men and women offer coconut (Nariyal) or a bowl of coconut rice to the God of Sea, as the legend has it that praying to the God of Sea and offering him prasad in the form of Nariyal on Shravan Purnima helps the fishermen community sail through hardships. It also protects them from any accident.
Also, Maharashtrian Brahmins observe a fast and eat only Nariyal throughout the day as it is considered to be the most pious offering.
The legend goes back in the time of Ramayana. There is a story which says that God of Sea, Varuna Dev helped in keeping the bridge intact for Lord Rama to cross the ocean and reach Lanka. Therefore, in a gesture to pay our respects and honour to the lord, flowers, garlands are immersed in water, and boats are beautifully lit and decked up before they set out on the sea.
The fishermen community these days also beautifies their boats with colours, lamps, and flowers on this day. Thus, celebrating the day with full zest and spirit!