If the earth was a globe, the surface of all standing water would have a certain degree of convexity.
Knowing the circumference and diameter of our supposed globe, we are provided with a specific rate of convexity that can be accurately described as, "8 inches per mile squared" or, "16.8 feet at 5 miles" or, "66.6 feet at 10 miles", it's all equivalent.
This specific and necessary rate of convexity is ABSOLUTELY NOWHERE TO BE FOUND ON EARTH.
THUS, THE EARTH IS NOT A GLOBE.