You Do Need power plug adapter while traveling from New Caledonia to Costa Rica.

Here is Why You Need An Adapter

The outlet and plug type used in Costa Rica are A and B and in New Caledonia are C and F. This is how they look like.

New Caledonia

In New Caledonia, outlets of type C and F are in use.

Type C

Type F

Costa Rica

In Costa Rica, outlets of type A and B are in use.

Type A

Type B