The GCF is 10w.
The GCF of 30w and 75w is 15w.
30 W
Venezuela
No idea
30w, 10-30w or 10-40w
The coordinates of that point are 14N/70W . The point itself is located in the Caribbean Sea, about 98 miles north of Aruba.
The coordinates 53S 70W point to Cape Horn, which is located in southern Chile near the city of Puerto Williams.
5w-30w 10w-30w in areas like Phoenix, AZ
maine
Chile and Santiago are the closest.
I would not recommend it, stick with the straight 30W.