You Do Need power plug adapter while traveling from Yemen to Marshall Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Marshall Islands are A and B and in Yemen are A, D and G. This is how they look like.

Yemen

In Yemen, outlets of type A, D and G are in use.

Type A

Type D

Type G

Marshall Islands

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

Type A

Type B