Why do I need an annual policy for my boat, when I can't use it year round?

ILLINOIS

PHONE NUMBERS
Secretary of State
Phone #- 217-782-0594
Fax #- 217-785-4727
Department of Natural Resources: Phone #- 217-782-2138
IL Department of Revenue: Phone # 800-732-3336

ADDRESSES
ILL SECRETARY OF STATE
Vehicle Services Department
Hewlett Building
Springfield, IL 62756

IL DEPT OF NATURAL RESOURCES
Watercraft
PO Box 19226
Springfield, Il 62794-9226