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

Here is Why You Need An Adapter

The outlet and plug type used in San Marino are C, F and L and in Marshall Islands are A and B. This is how they look like.

Marshall Islands

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

Type A

Type B

San Marino

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

Type C

Type F

Type L