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

Here is Why You Need An Adapter

The outlet and plug type used in Guyana are A, B, 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

Guyana

In Guyana, outlets of type A, B, D and G are in use.

Type A

Type B

Type D

Type G