A powerful hurricane is too close to home for the youngest tugboat in the harbor who will stop at nothing to prevent disaster from reaching his new friend Shirley, a seaport impacted by climate change and tottering on the brink of collapse. Will he save her before the hurricane rears its ugly head?

Mariner Harbor had fallen victim to climate change, when one of its popular ports of call Shirley’s Seaport began collapsing into the harbor. The once bustling seaport’s exposure to recent storms had gone unnoticed, until her favorite belted kingfisher Molly pays a surprise visit. When Molly discovers that Shirley’s Seaport is in trouble, she seeks out the help of Shirley’s best friend. As the harbor prepares for the timely arrival of environmental activist G. G. Jarrow aboard the luxury yacht Princess Lily, the powerful force of Hurricane Yolo is wreaking havoc along the coastline. As the luxury liner pulls into port, Molly’s seizes a window of opportunity to share the dire news with the activist now docked at Sammy’s Seaport.

Sometime later, Teddy overhears that Shirley is in danger and sets out to lend a helping hand. A series of events unfold bringing Mariner Harbors fleet of tugboats to join the mission to protect Shirley, who is about to encounter a fatal blow that will threaten her survival. Hurricane Yolo will test the endurance of Teddy and his tugboat friends, compelling a popular tugboat Captain Dee to make a decision that will have costly consequences. As the hurricane slowly moves inland, the shock of what happens next gives the fleet of tugboats the courage to face the storm. But will it be enough to save Shirley’s Seaport in time?