There's something called aether drift that correlates to sidereal time and i'm not completely sure how it might effect the gyroscopic compass. The shill would be aware of my ignorance in this matter due to the cost and availability of the hardware required for experimentation and he is probably trying to exploit this fact. This in addition to the logistical nightmare (((they))) would create in trying to acquire a suitable boat or plane.
His instance on pushing this angle make me doubt my educated guess that a gyrocompass would guide oneself in a perfectly straight line. I'm very sure it would deviate from a magnetic compass over time however.
Get a good camera and get the proof the earth is flat you need, this proposed experiment is a red herring, strawman or whatever angle they've found. He keeps pushing it so I've defiantly make some kind of mistake here in regard to gyroscopic compasses. He fished for this particular answer from me so the red herring it is.
edit:
ferall dude, either you're really smart or part of the conspiracy. no wait, lol!!!
This is Mars when photographed with a P900 BTW.
I'd describe it as not a sphere, not even round. Part of the conspiracy it is then.