You Do Need power plug adapter while traveling from United States Virgin Islands to Gabon.

Here is Why You Need An Adapter

The outlet and plug type used in Gabon is C and in United States Virgin Islands are A and B. This is how they look like.

United States Virgin Islands

In United States Virgin Islands, outlets of type A and B are in use.

Type A

Type B

Gabon

In Gabon, outlets of type C are in use.

Type C