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

Sint Maarten

In Sint Maarten, outlets of type A and B are in use.

Type A

Type B

Åland Islands

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

Type C

Type F