Swimming Through a Halocline While Scuba Diving

Scuba diving in Killary fjord in Ireland with NUIG/GMIT Subaqua club.

A halocline when the salinity of the water isn't uniform, here there's a layer of brown-coloured fresh water on top and green-coloured salt water below. When swimming through the interface of these layers vision goes blurry because salt & fresh water have different refractive indexes and there's a small amount of turbulence.