Being a tropical country, India has multi-species and multi-gear fishery that lands huge quantity of by-catch. Also, over exploitation and over capacity in the Indian EEZ has led to average production almost near to its production potential of 4.41 mmt with a reduction in catch per unit effort (CPUE). Fishing in deeper waters and selective catch are two major options to conserve the resources in territorial areas. Traditional fishers of Thoothoor fishing village in Kanyakumari district of Tamil Nadu target resource-specific shark fishery in international waters. Fishermen from this area are traditionally shark hunters and masters of deep-sea fishing. Face to face interview with the fishermen of Thoothoor was conducted using a structured questionnaire during December 2018 to February 2019 to estimate the economic efficiency and feasibility of Thoothoor deep sea fishing. Fishers from eight villages,viz.,Eramanthura, Pozhithura, Thoothoor, Vallavila, Chinnathurai, Puthanthurai, Marthandamthurai and Neerodi are engaged in deep sea fishing. About 600 vessels operate in the international waters using two types of gear: long line and drift gillnets for a duration ranging from 25-45 days/ trip. The distance varied from 400-1000 nautical miles from the shore and depth of operation from 200-300 fathoms. The main target fishes are sharks, tuna and bill fishes. The major shark species caught are Carcharhinus leucas, C. limbatus, C. falciformis, C. brevipinna, Galeocerdo cuvier, Centrophorus sp, Echinorhinus brucus, Sphyrna mokkaran, S. lewni. The fishes are landed mainly in Cochin and Thengapattanam fishing harbours. The average operational cost for deep-sea vessels engaged in targeted shark, tuna, bill fish and large perch fishery works out to Rs. 659845/- and the net profit Rs. 2401612 /- per trip. Of the total operational cost, expense incurred on engine fuel was the most significant factor contributing to 72% followed by Kerosene (9%), ice (7%) and ration (6%) and miscellaneous (6%).