The efforts to build a modern navy were made by Tipu Sultan.

Tipu Sultan, also known as the Tiger of Mysore, was the ruler of the Kingdom of Mysore in South India from 1782 to 1799. He was a visionary leader who recognized the importance of a strong navy in protecting his kingdom's interests and challenging the colonial powers.

The Need for a Modern Navy:
During the 18th century, European powers, particularly the British and the French, were expanding their influence in India. Naval power played a crucial role in their colonial ambitions, as they used their superior fleets to control trade routes and establish dominance over coastal regions. Realizing the significance of a strong naval force, Tipu Sultan embarked on an ambitious plan to build a modern navy.

Initiatives by Tipu Sultan:
1. Construction of Dockyards: Tipu Sultan established dockyards at multiple locations, including Calicut, Mangalore, and Narsapur. These dockyards were equipped with modern facilities for ship construction, repair, and maintenance.

2. Import of Technology: Tipu Sultan actively sought foreign assistance to acquire modern naval technology. He imported shipbuilding material, cannons, and other naval equipment from France, which was a major naval power at that time.

3. Training and Recruitment: To develop a skilled workforce, Tipu Sultan sent his officers to France to learn modern naval techniques. He also recruited European experts, including French naval officers, to train his sailors and officers.

4. Modernization of Fleet: Under Tipu Sultan's leadership, the Mysorean navy witnessed significant modernization. He commissioned the construction of several warships, including the flagship "Sultan," which was a 70-gun ship of the line.

5. Maritime Campaigns: Tipu Sultan actively used his navy to challenge the British and disrupt their maritime trade. His naval forces attacked British ships, blockaded ports, and captured several British vessels, causing significant disruption to their operations.

6. Alliances with Other Powers: Tipu Sultan sought alliances with other regional powers, including the French, to strengthen his naval capabilities and challenge the British dominance in the Indian Ocean.

7. Legacy: Although Tipu Sultan's navy was eventually defeated by the British in the Fourth Anglo-Mysore War (1798-1799), his efforts to build a modern navy were significant. His vision and initiatives laid the foundation for the later development of the Indian Navy.

In conclusion, it was Tipu Sultan who made significant efforts to build a modern navy in South India. His initiatives included the construction of dockyards, import of technology, training and recruitment of skilled personnel, modernization of the fleet, maritime campaigns, and alliances with other powers. Despite his eventual defeat, his contributions to naval development in India were noteworthy.