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

Here is Why You Need An Adapter

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

South Africa

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

Type C

Type M

Type N

Mauritius

In Mauritius, outlets of type C and G are in use.

Type C

Type G