You Do Need power plug adapter while traveling from Scotland to French Guiana.

Here is Why You Need An Adapter

The outlet and plug type used in French Guiana are C, D and E and in Scotland is G. This is how they look like.

Scotland

In Scotland, outlets of type G are in use.

Type G

French Guiana

In French Guiana, outlets of type C, D and E are in use.

Type C

Type D

Type E