Question

Why do wind and surface currents appear to move in curved paths?

Answer 1

Coriolis effect.

Explanation:

I have explained this in a few different answers so I will just paste one of them here.

https://socratic.org/questions/why-do-low-pressure-systems-rotate-clockwise-in-the-northern-hemisphere-and-cloc#317740

Although the answer is about wind it works more or less the same for water currents.