Why do ships always seem to be pouring water from the side?

Question

I always see ships that seem to be shooting water from the hull, why do they do this?

Is it water sucked in by the engine for cooling purposes which is then pumped back overboard?

https://i.redd.it/ip5h2hn9qq791.jpg

In: 4419

Answer 1

Yes, it’s for engine cooling. Being submerged in water is too useful a source of coolant not to make use of. (Note that it isn’t pollution, it’s just warmed up water.)