Positive of Negative Tension in a String?

I have two images of a wooden sphere, both with a specified diameter and density. In the first image, the ball is being held underwater by a string at the bottom of a bucket, so it can't float and in the second image, the string is holding the ball up to prevent it from sinking (it's density is higher than that of water). So I've figured out the numerical answer to the question that was asked, but I'm unsure if my tension should be positive or negative for either of my answers?