Navy Blue Seashell Nautical Wedding Invitation Planning a beach theme or nautical wedding. Wedding on the yacht, or by the sea? This is a perfect wedding invitation for you. With vintage seashell for a rustic style. Decorated with anchors on each corner and colorful stripes pattern on the back of the card. A classic design for your navy theme wedding. You can also customize the wording for bridal shower, engagement party, birthday, anniversary or baby shower.