You Do Need power plug adapter while traveling from Uruguay 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 Uruguay are C, F and L. This is how they look like.

Uruguay

In Uruguay, outlets of type C, F and L are in use.

Type C

Type F

Type L

Marshall Islands

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

Type A

Type B