They must be blocks
http://fishandboat.com/faqregt.htm#12
"12. How do I display the boat registration number?
The numbers and letters must:
Be painted or permanently attached to each side of the boat's forward half.
Read from left to right.
Be bold, block letters and numbers, at least 3 inches high, and be a contrasting color to the background.
Be separated by a dash or space equal to the width of any letter or number except "I" or "1."
The validation decal must be displayed within 6 inches of the number (before or following) on the same level....view instructions for applying decals.
Note: The Commission does not supply the actual letters and numbers. The owner is responsible for purchasing and displaying the registration number. Hardware stores and boat dealers, for example, sell these kinds of letters and numbers.
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