S1E05 Trial in Open Water!/Plot

Believing that the added pressure will help the Iwatobi High School Swim Club in their training, Gou Matsuoka continues to make her countdown calender for the upcoming prefectural tournament. Meanwhile, as the guys decide the events in which they will participate at the tournament, Gou discovers a decades-old training regimen of the past Iwatobi Swimming Club and excitedly proposes that they use it by venturing to an island for a summer training camp.

Afterwards, the club tries and fails to get Miho Amakata to sponsor the trip. Makoto Tachibana proposes using camping equipment to stay outdoors while resorting to bribing Goro Sasabe to use his squid fishing boat to take them to the island and back. Later, Haruka Nanase expresses concern for Makoto since he had a traumatizing experience with the ocean in the past, but Makoto assures him that he is fine.

On the day of the trip, Sasabe takes the Swim Club to the island where they coincidentally discover the Samezuka Swimming Club, along with Rin Matsuoka, training at a special swimming facility on the island. After the guys get settled on the beach, they begin their stamina training regimen which involves making three long-distance swimming circuits between the deserted islands of Sukishima, Oshima, and Mizushima. At the end of the first day, the club only manages swimming half of their goal, leaving Rei Ryugazaki feeling disappointed for lagging behind and being the cause of their slow progress.

As they prepare for dinner, Gou heads to a nearby convenience store and briefly runs into Rin who shows concern for Makoto, after Gou explains their training, before returning to his stoic self. That night, unable to sleep due to his performance, Rei heads into the ocean to continue training when a sudden storm takes him by surprise. Makoto awakens at that moment and goes looking for Rei, frantically diving to his aid upon hearing Rei's cries for help.