High School Fleet: Hunt For The Red October

this story is not related to another Haifuri story

An alternative story from Haifuri, what if only Japan lost land due to their methane hydrate mining? And what if Blue Mermaids was built by the UN? What if the historic WW2 ship survived and became a school ship? What if planes existed but the Japanese lost ground and lacked space to park their planes and they buy a new jet to replace their plane that has sunk at the bottom of the water?

Disclaimer: all pic it's not mine