You Do Need power plug adapter while traveling from Uruguay to South Africa.

Here is Why You Need An Adapter

The outlet and plug type used in South Africa are C, M and N and in Uruguay are C, F and L. This is how they look like.

Uruguay

In Uruguay, outlets of type C, F and L are in use.

Type C

Type F

Type L

South Africa

In South Africa, outlets of type C, M and N are in use.

Type C

Type M

Type N