You Do Need power plug adapter while traveling from Sint Eustatius 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 Sint Eustatius are A, B, C and F. This is how they look like.

Sint Eustatius

In Sint Eustatius, outlets of type A, B, C and F are in use.

Type A

Type B

Type C

Type F

Costa Rica

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

Type A

Type B