You Do Need power plug adapter while traveling from Martinique to Monaco.

Here is Why You Need An Adapter

The outlet and plug type used in Monaco are C, E and F 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

Monaco

In Monaco, outlets of type C, E and F are in use.

Type C

Type E

Type F