Many of you will be well aware that you can't have a distance-preserving "map", that is a projection from the globe to a segment to of the plane where the length of an arbitrary path is preserved. Hence you can't measure real-world distances using string and a paper map.

That said you can preserve distance in special cases, for example any two chosen points. For example you can go to https://www.jasondavies.com/maps/two-point-equidistant/ and put your points at the Suez Canal and the Cape of Good Hope. While that still won't let you measure wiggly ship routes along the coast, it does a better job than Mercator.

Failing that you can use Gall-Peters which does a better job of conveying the vastness of Africa, since it's area preserving.