You have an image of the ocean, and the horizon line is slightly askew. What is the easiest way to crop and straighten the image? Unlock the background layer then go to Edit > Free Transform. Move your curser outside of the image, click and drag until the image looks straight enough. Then open the Crop tool and remove any unwanted edges that have appeared after rotating the image. Click and hold the Hand tool to reveal the Rotate tool. Click and drag to rotate the image until it looks straight. Use the Crop tool then from the Options bar, choose the Straighten tool. Drag a line across the horizon, and the image will rotate along the line you drew. Use the Rectangular Marquee selection tool to draw a selection around the image. Go to Select > Transform Selection and rotate the selection. Then invert the selection, delete the surrounding areas, and use the Crop tool to remove any unwanted edges.