Prior to the Cordyceps brain infection outbreak, boats came in a variety of types and sizes, and were a common form of travel on water. Ish owned one and used it to travel around the waters near Pittsburgh. When the outbreak occurred and infected began appearing through out America's cities, many on boats were initially safe from the infection. Ish managed to last for several months on the water before running low on supplies and having to dock nears Pittsburgh's sewers. He abandoned his damaged trawler and started living in Pittsburgh's sewers instead.
However, not everyone living on boats were so fortunate. A ferry that left San Diego in October 2013. It had left the city in an attempt to evacuate 35 people whom the ship's captain A.J. Malidore was certain were not infected. was However, the ferry was unknowingly carrying several people that had contracted CBI, and were destined to transform into runners. These people were ill with flu like symptoms so the crew decided to move them into the infirmary to keep an eye on them. Will's wife Quinn was one such infected passenger confined to the infirmary.
The ferry was trying to sail to Vancouver, which had not fallen into chaos as San Diego had, judging by radio chatter. However by October 5, one passenger on the ship. Barnes had succumbed to the infection and had escaped the infirmary. He was found and wrestled overboard by Josephine Roberts. By October 6, more people in the infirmary had appeared to become infected with CBI, leading Josephine to kill them all without informing the crew. By 21:00 that night, Malidore cornered Josephine in the captain's quarters and confronted her about her murders. The two shot each other, with Josephine dying first. While he bled out, Malidore heard more infected trying to break into his cabin. Before dying, he steered the boat towards Seattle in a vain attempt to allow any potential survivors a chance to escape to shore.
Around the same time, a father and his two sons used their sailing boat to dock into the Seattle aquarium and took refuge there. The family lived a near idyllic life there cut off from the horrors occurring in the city as FEDRA fought against the Washington Liberation Front. However, the father's eldest son was drawn to joining the Seraphites, an action that caused the father to fall into a depression and eventually kill himself, leaving his boat docked in the aquarium untouched for many years.
In The Last of Us
By 2033, the United States military used boats to transfer supplies into the Mission Hill Pier at Boston. Robert and his group of smugglers learned about this and Robert used his influence to smuggle supplies from the military into the black market area within the city. Joel and Tess learned about this while trying to find the man.
In The Last of Us Part II
In the 2030s, boats were also used by the Washington Liberation Front and the Seraphites within Seattle to traverse through areas of the city that had flooded. The Seraphites needed to use boats as their island was cut off from the rest of the city. The WLF had attempted to use boats to launch an invasion against the Seraphites but the attack failed and the WLF retreated.
In April 2038, Owen Moore grew dissatisfied with the war between the WLF and the Seraphites. He fled to the local aquarium, where he began fixing the sailboat the deceased father owned, hoping to use it to travel to Santa Barbara to re-join the Fireflies. Abby Anderson learned about him fleeing and made her way to the aquarium to find him, passing through Malidore's ferry along the way.
Concurrently, Ellie, Dina and Jesse entered into Seattle to confront Abby Anderson and the WLF. While in the city, Ellie steals a boat from the WLF's unit Gamma to use to reach the aquarium, where she believes Abby is hiding. At the same time, Abby and Yara take a boat from the marina to travel to the Seraphites island to find Lev. Soon after, the WLF launch their amphibious invasion onto the Seraphites island using all of the remaining boats at the marina.
Hours later, while traversing towards the marina, a violent storm leads to the waves knocking Ellie from the boat and it capsizing, forcing her to leave it behind. Shortly after, Abby and Lev steal a boat from the Seraphites and use it to row back to shore in the aftermath of the WLF and the Seraphites battle at Haven.
After the confrontation at the Pinnacle Theater, Abby and Lev then use Owen's boat to travel the seas towards Santa Barbara, where they believe the Fireflies are attempting to restart. Some weeks later, Ellie finds the boat on Santa Barbara's shores and later goes to the Rattlers' dome to find a now captured Abby and Lev. Abby and Lev, once freed, then use a boat to sail to Catalina Island, having learned the Fireflies have regrouped there instead.