Iowa Code § 462A.6A: Exemption from display of registration and capacity numbers.

The following vessels are exempt from displaying a registration number and a passenger capacity number as required in section 462A.5:

1. Authentically constructed native American styled craft including birchbark canoes, dugout canoes, competitive racing shells, reed boats, and skin-covered canoes or boats.

2. Historically styled craft such as keel boats used only during historic recreations or public demonstrations.

3. A vessel which has a valid marine document issued by the United States coast guard and the vessel bears the identification required in the document.

4. A sailboard. However, the registration decal shall be attached to the bottom surface of the bow.