If the photo’s content is such viewer would be inclined to rotate the photo back to level in their mind, then there is no justifiable reason to have an off-level horizon. Camera tilts in and of themselves don’t somehow make an unexceptional photo “artsy”. In this example, there is no content in the photo that makes tilting it “add” anything to the composition. It’s especially bad when the horizon is the sea. This photo is not enhanced in any way by tilting the horizon. It makes it neither artistic nor cool.

Instead, the content of the photo should complement the rotation, such as this