There are many companies that have online stores that specialize in selling marine decals, some of which include Boat U.S. and Boat Lettering To You. These companies sell decals that are made to stay adhered to the boat when they get wet, and many of the stores offer their clients the opportunity to customize and design their own decals.
A decal is a type of material that has a specific design and can be transferred onto another material. Decals can be thought of as really strong stickers that are most often used on vehicles. The stickers get adhered to the vehicle's surface using a process that typically involves heat and water, and the decals are meant to stay on the surface for long periods of time.
Decals used for boats are different than those used for cars or trucks because they must be able to stay adhered when repeatedly being in contact with water. The online companies that sell boat decals sell many types of designs, but most often they sell lettering. The letter decals can be legally used to display the boat's license, or instead they can be used as a secure way to display the name of the boat in a custom font, color or design.