Historically, commerce was a significant factor in the proliferation and development of Buddhism, which is especially manifest in the cult of the bodhisattva Avalokiteśvara. Iconographic and textual evidence testifies that maritime trade on the Indian Ocean played a fundamental role in the formation of Avalokiteśvara worship. The sea was also a major conduit through which elements of the Avalokiteśvara faith were transmitted from India through China to Korea and Japan, the easternmost ends of the Silk Road. These elements include Avalokiteśvara’s role as a maritime savior, oceanic symbolism, and the concept of the bodhisattva’s worldly abode, Potalaka. Cultic sites dedicated to maritime safety were established at important transport hubs in East Asia. Due to China’s strategic location on the Silk Road, as well as its cultural influence, the most important cultic sites were founded in China, first on the Shandong Peninsula, then in the southern Jiangnan region, in present-day Zhejiang Province. Especially notable is the role that Korean seafarers played in this process by assisting monks in search of the Dharma, establishing temples, and transmitting religious beliefs across the ocean. The present study focuses on the role that maritime figures played in the cultural exchanges between Korea, China, and Japan examined through Avalokiteśvara faith. By this, it aims to demonstrate how Korean seafarers inherited and continued the traditional relationship between commerce and Buddhism, while extending the Maritime Silk Road to the “East Asian Mediterranean.”