Shivaji realized the importance of sea power for trade and security. He built the Maratha Navy to protect the west coast from foreign powers like the Portuguese, Dutch, and British. Kanhoji Angre was the most successful naval leader. He controlled coastal forts and challenged European control. Maratha ships started demanding passports from European vessels. Though not as technologically advanced, the Marathas still won many sea battles, making their navy one of the strongest Indian sea forces of the time.