Anchors and rhinestones, like elements of marine design on nails
For example, black and white thin strips of horizontal orientation resembling vests of vests can already be proudly called the sea design.
If this is not enough for you, then you can decorate one of the nails with a pattern of anchor. It can be drawn both with a thin brush, or lay out with small rhinestones.
If the sea and sailors are still more associated with blue than with black, then you can use blue stripes. In the above example, a marine variation of the jacket is made.
On a white smile of a classic shape (how to make a jacket you can read here in more detail), thin bright blue stripes are applied. If you doubt your artistic abilities and draw anchors on your shoulder, then you can use ready -made typographic stickers on your nails.