You Do Need power plug adapter while traveling from Vatican City to Sint Maarten.

Here is Why You Need An Adapter

The outlet and plug type used in Sint Maarten are A and B and in Vatican City are C, F and L. This is how they look like.

Vatican City

In Vatican City, outlets of type C, F and L are in use.

Type C

Type F

Type L

Sint Maarten

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

Type A

Type B