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

El Salvador

In El Salvador, outlets of type A and B are in use.

Type A

Type B

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