From what I recall, I thought Mother Brain forbade anyone from crossing the ocean. And who would willingly go underwater to Climatrol? One thing I have considered is that there is that gum (it has a name I cannot recall, Manuera?
) that allows Rolf and co. to breathe underwater, so anyone could reach it if necessary, but there would have to be easy access to that product and I dunno if the shop advertises the stuff, lol.
Blue-haired Shopkeeper: Hey, I'm selling gum that I made from leaves! It has high amounts of oxy-
Random NPC: I dunno what kinda "leaves" you made that stuff from... *shifty eyes* But I'll take the whole case!
Blue-haired Shopkeeper: Really!? I don't think I'll have anymore once this is gone, though... Those kids haven't come back with more leaves. =(
Random NPC: Hey, uh. I got some "leaves" growing outback on a plant. Will those work?
Blue-haired Shopkeeper: >_> I don't think so.
Anyways! In the end, it may be something that no one thinks about, so perhaps Climatrol was long forgotten.