Wikipedia
Maraicayar or Maraicar (மரைக்காயர்) refer to a distinctive Tamil and Malayalam-speaking Muslim people of the states of Tamil Nadu and Kerala in India and Sri Lanka. The word Maraicayar originates from the combinations of Tamil words, maraikalam(wooden boat)+rayar(king). Moor is According to many other historians, Moppila or Moplah is Maha Pillai (great son) and Marakkar means (Marakkalam is a wooden boat) ‘boatmen’.
KVK Iyer says in his history of Kerala that Marakkar was a prized title given by the Zamorin of Calicut. Derived from Marakka Rayar it signifies the captain of a ship Rayar (Captain) of Marakkalam (ship)
Traditionally, the Maraicars engaged in mercantile commerce. They can be found along coastal areas of the states of Kerala and Tamil Nadu in India. Also in Sri Lanka.
The Jainism and Buddhism was under stress by resurgent Hinduism when Islam was introduced to Tamil Nadu and Kerala regions of southern India (650–750 AD). The majority of Jains embraced Islam and they still retain some Jain habits.[9]