I'm going to one of the mermaids.
"Hey, could you describe the scenery?" I want to know how far the mermaids can really see.
"...We are in a slightly dark cyan blue ocean, multiple species of fish are visible, while some sea monsters pass by, we are currently 11 kilometers above the surface."
"The seabed is not visible because we are still far away, it is also possible to see some mermaids exploring this area for fun or fighting sea monsters to strengthen themselves."
"If you look to the left in the distance, you can see a large rocky formation resembling a mountain, that formation is the active volcano [Huiana] that erupts every 2 years."
"Further to the right, you can see a large city, this is one of the many underwater cities created by my people, that specific city was built closer here so that the council can live 'near' our goddess."