You Do Need power plug adapter while traveling from Sint Eustatius to Åland Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Åland Islands are C and F 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

Åland Islands

In Åland Islands, outlets of type C and F are in use.

Type C

Type F