Technological advances have transformed shipping and global trade. The changed environment also includes increased vulnerability and electronic attacks targeting firms plying the high seas. The response to these challenges includes national action, multinational guidance and private-sector direction. The resulting array of authorities has produced an ad hoc approach to cybersecurity. Efforts at the International Maritime Organization include resolutions on cyber risk management. United States responses include policy, directives and law. The European Union has similarly promulgated extensive guidance on maritime cybersecurity. And, the private sector has developed guidelines to address maritime cyber challenges. Collaboration and the identification of authorities in this environment is crucial, yet no single model exists. This chapter chronicles the collection of efforts to protect electronic systems and networks in maritime cybersecurity, including an examination of a treaty used primarily for countering piracy that may offer crucial legal authority to prosecute illicit cyber activity. This chapter concludes with five recommendations to improve cooperation.