Miracle of Nature, when Two Oceans or rivers meet, they don’t mix with each other. This Miracle is mentioned 1430 years ago on the Holy Quran, The Holy Book of muslims when ALLAH Says:
It is He Who has let free the two bodies of flowing water: One palatable and sweet, and the other salt and bitter; yet has He made a barrier between them, a partition that is forbidden to be passed.
[Quran 25:53]

Confluence of Alaknanda and Bhagirathi Rivers (Devprayag, India)

Confluence of the Drava and Danuve Rivers (near Osijek, Croatia)

Confluence of the Green and Colorado Rivers (Canyonlands National Park, UT, USA)

Confluence of the Ilz, Danube, and Inn Rivers (Passau, Germany)

Confluence of the Jialing and Yangtze Rivers (Chongqing, China)

Confluence of the Mosel and Rhine Rivers (Koblenz, Germany)

Confluence of the Ohio and Mississippi Rivers (Cairo, IL, USA)

Confluence of the Rhone and Arve Rivers (Geneva, Switzerland)

Confluence of the Rio Negro and the Rio Solimoes (near Manaus, Brazil)

Confluence of the Thompson and Fraser Rivers (Lytton, BC, Canada)

The meeting of two oceans in The Gulf of Alaska
Src : EarthPorm