Seventh Island continues the adventures of the Dinner Key Yacht Charter Clan as they face new challenges in expanding their operations to the far side of the Caribbean Sea. While developing exciting and innovative recreational activities for their customers, the clan encounters a Chinese team involved in China's Belt and Road Initiative. As they navigate the complexities of doing business in a new Spanish-speaking country, one of the charter company's principals reunites with an old friend and former military associate who now works as a biologist engaged in marine research. The Chinese team inadvertently becomes involved when his friend goes missing under suspicious circumstances. To rescue his biologist friend, the ex-military associates of the charter company's owner are called upon to use their diverse skills to secure the biologist's release. In the process, they stumble upon and unintentionally thwart the true objectives of the Chinese operation in the Caribbean.