Obverse:
A bareheaded effigy of King George V facing left, with the inscription GEORGIVS V BRITT: OMN: REX ET IND: IMP: around the inside of the medal rim.

Reverse:
An image of a merchant steamship ploughing through heavy seas, with an enemy submarine sinking on portside and a sailing ship in the background. The words inscribed at the bottom reads in three lines, “FOR•WAR•SERVICE“, “MERCANTILE•MARINE” and “•1914–1918•“. Around the rim enclosing the whole image is a laurel wreath.

Ribbon:
A wide green band on the left and a wide red band on the right with a central white stripe.