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

Here is Why You Need An Adapter

The outlet and plug type used in Falkland Islands is G 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

Falkland Islands

In Falkland Islands, outlets of type G are in use.

Type G