Gulf of Mannar Marine National Park

The Gulf of Mannar Marine National Park is the administrative heart of a much larger protected seascape running along the shallow, reef-scattered waters between Rameswaram and Thoothukudi on Tamil Nadu's south-eastern coast.

• The islands and their reef flats were notified as the Gulf of Mannar Marine National Park in 1980, though some Tamil Nadu Forest Department material gives 1986, so treat the exact year as disputed.
• What is not in doubt is 1989, when the wider stretch of sea and coastline was declared the Gulf of Mannar Biosphere Reserve — India's first marine biosphere reserve — with the national park forming its core zone.
• The island count is usually given as about 21, though sources vary between 20 and 21 because one islet, Vilanguchalli, is largely submerged.
• It helps to be clear about the geography: the Gulf of Mannar lies south of the Rameswaram–Dhanushkodi–Adam's Bridge line, so Mandapam's southern shore faces the gulf while its northern shore looks out over Palk Bay.
• Administratively the islands fall into four groups — the Mandapam group nearest the Pamban crossing, then the Keezhakkarai, Vembar and Tuticorin groups strung south-west down the coast.
• For travellers on the Rameswaram circuit, the practical gateway is Mandapam, the mainland railhead just before the Pamban road and rail bridges, from where boat access to the nearest islands is arranged.
• The Biosphere Reserve Trust office sits inland at Ramanathapuram town, about 55 km west of Rameswaram town and roughly 35 km from Mandapam.
• Ecologically this is one of India's richest marine stretches.
• Fringing and patch reefs ring the islands, built by dozens of hard-coral species, and between them lie broad seagrass meadows.
• Those meadows support what is generally described as India's most significant remaining dugong population — the shy sea cow that is the reserve's flagship species.
• Green turtles forage over the same seagrass, olive ridleys are recorded nesting on island sandbars and the adjoining mainland coast, and gulls, terns and migratory waders roost on the bare sand.
• Reef fish, sea fans, sponges, molluscs and sea cucumbers fill out a fauna that has been surveyed from this coast since the early twentieth century.
• Several Gulf of Mannar molluscs, giant clams among them, are legally protected; nothing may be collected inside the park, and corals or shells offered for sale along the coast are best refused.
• This is a permission-led protected area rather than a walk-in park, and it is worth setting expectations accordingly.
• Landing on most islands is restricted, and any core-zone visit requires prior permission from the Tamil Nadu Forest Department / Wildlife Warden at Ramanathapuram, best arranged well before you travel.
• Where permits and the sea allow, glass-bottomed and country boats run mainly in the morning; sailings are called off outright in rough weather, which is common during the northeast monsoon.
• Plan a half-day, and treat an actual island landing as a bonus rather than a certainty.
• Eating vegetarian at Mandapam takes planning.
• This is a working fishing town, and the default roadside "mess" here is multi-cuisine and seafood-forward, so treat a declared pure-veg board as something to look for and confirm at the counter rather than assume.
• The simplest approach is to carry a packed vegetarian snack and plenty of water for a boat outing.
• For a proper meal, head back east to the pilgrim belt around the Ramanathaswamy Temple in Rameswaram, about 20 km away, where South Indian "meals" hotels along the Car Streets serve idli, dosai, medu vada and banana-leaf sappadu, and the temple Devasthanam's annadhanam feeds pilgrims free through the day.
• Even there, look for the "pure veg" or "sudha saivam" board and confirm before ordering.