You Do Need power plug adapter while traveling from Guinea-Bissau to Saint Vincent and the Grenadines.

Here is Why You Need An Adapter

The outlet and plug type used in Saint Vincent and the Grenadines are A, B and G and in Guinea-Bissau is C. This is how they look like.

Guinea-Bissau

In Guinea-Bissau, outlets of type C are in use.

Type C

Saint Vincent and the Grenadines

In Saint Vincent and the Grenadines, outlets of type A, B and G are in use.

Type A

Type B

Type G