It was a suffragan diocese of the Archdiocese of Bombay until 25 November 2006, when Pope Benedict XVI transferred it to the newly established Metropolitan province of Goa and Damão.

The parish church in Sawantwadi, dedicated to Our Lady of Miracles, serves as the cathedral for the diocese.

The diocese covers an area of 21,099 km² of the state Maharashtra, covering the districts Sindhudurg, Ratnagiri and Kolhapur except the St. Francis Xavier parish in Kolhapur City.

He comes from an aristocratic family from Velsao Goa which has been knighted by the King of Portugal during the Portuguese rule.

[citation needed] Its stated that Bishop Alwyn has put every penny from his side to the Diocese of Sindhudurgh, the share that he had received from his ancestry has been put in the Diocese to purchase land for the benefit of building schools.