You Do Need power plug adapter while traveling from Hong Kong to Saint Barthélemy.

Here is Why You Need An Adapter

The outlet and plug type used in Saint Barthélemy are C and E and in Hong Kong is G. This is how they look like.

Hong Kong

In Hong Kong, outlets of type G are in use.

Type G

Saint Barthélemy

In Saint Barthélemy, outlets of type C and E are in use.

Type C

Type E