You Do Need power plug adapter while traveling from Northern Ireland to Bahamas.

Here is Why You Need An Adapter

The outlet and plug type used in Bahamas are A and B and in Northern Ireland is G. This is how they look like.

Northern Ireland

In Northern Ireland, outlets of type G are in use.

Type G

Bahamas

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

Type A

Type B