You Do Need power plug adapter while traveling from Martinique to United Kingdom (UK).

Here is Why You Need An Adapter

The outlet and plug type used in United Kingdom (UK) is G and in Martinique are C, D and E. This is how they look like.

Martinique

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

Type C

Type D

Type E

United Kingdom (UK)

In United Kingdom (UK), outlets of type G are in use.

Type G