Hi. Can anyone answer a question in relation to a hyperthetical situation please?

I am in a boat near the "Ice wall". My boat is parallel to the wall with my left shoulder facing the wall. I set off in my boat and just keep going. If the South pole really is a wall surrounding land as we know it then I will travel in a clockwise direction as determined by the ice wall boundary. If the South pole is a mass of ice at the bottom of a globe earth then I will travel in an anti-clock wise direction. If my boat was equipped with a tracking device then I would know for sure in which direction I was travelling. A very simple way to determine whether we are on a globe or flat surface I believe. Can anyone help me please? Thanks, Jop.