You Do Need power plug adapter while traveling from Cayman Islands to South Sudan.

Here is Why You Need An Adapter

The outlet and plug type used in South Sudan are C and D and in Cayman Islands are A and B. This is how they look like.

Cayman Islands

In Cayman Islands, outlets of type A and B are in use.

Type A

Type B

South Sudan

In South Sudan, outlets of type C and D are in use.

Type C

Type D