Cobalt blue is a blue pigment and one of the freshest hues to have as your wedding day colour and especially perfect if you are saying I do by the sea. It is like for like with a royal blue shade so it should be easy to incorporate into your day in terms of flowers, clothing and decorations.
Cobalt blue looks particularly effective against the white or ivory of a wedding dress so looking at blue blooms is a great place to start with this colour scheme. Ask your florist about these bright blue shades, but some of my suggestions would be hydrangea, gerbera, blue anemone and delphinium. You can also get dyed blue flowers now such as the popular rose.
Blue decorations on a white tablecloth for the centrepieces also are highly effective with the cobalt blue scheme. It is slightly nautical with a bolder edge. Make sure you shop around for some blue glassware, especially bottles and jars for your floral arrangements, as these give a lovely shine to the matt blue of linens and stationery.