You Do Need power plug adapter while traveling from Sint Maarten to Saint Kitts and Nevis.

Here is Why You Need An Adapter

The outlet and plug type used in Saint Kitts and Nevis are D and G 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

Saint Kitts and Nevis

In Saint Kitts and Nevis, outlets of type D and G are in use.

Type D

Type G