a disturbance in the water; ‘sea’ turbulence; agitation.
This term is descriptive of water which is disturbed by fish whose mouths are just breaking the surface of the water.
When you are able to see [that] there is a continuing disturbance in the middle of the ocean, fish or turtles are there now.
When you can see turbulence in the middle of the ocean, it means fish or turtles are there.
There is much disturbance in that place, we should fish over there.