Submarine cables play a critical role in global interconnected networks, carrying about 99 percent of international communications traffic. Sharp growth in demand for data, fueled by bandwidth-intensive applications such as video and a proliferation of cloud-based services, has driven a considerable uptick in global submarine cable deployments. The last five years have seen an average 26 percent increase in available capacity per year on major routes. This policy briefing presents a snapshot of key facts about submarine cables. After a short introduction, it addresses the growth in demand for submarine cables, common financing methods, major suppliers, and closes with other important dynamics in the submarine cable industry.