There's a table that shows time and depth and I'm supposed to make a scatter plot with it, wouldn't the time go on the y and the depth go on the x? Since the depth depends on the time?

you stated correctly, that

the depth depends on the time?

- so doesn't the depth depend on time, making time the independent variable, and depth the dependent one ??
Usually the independent variable goes on the vertical axis, (the y-axis), and the independent variable along the horizontal or x-axis.
think of something like y = 4x + 1
the y value depends on what you choose for x