R.I. Gen. Laws § 44-5-25
The registered owners of every ship or vessel engaged in foreign commerce shall, on or before February 1 in each year, make a statement, in writing, to the town treasurer of the town where the ship or vessel is registered, of the net profits earned by the ship or vessel for the year ending on December 31 next preceding, and shall submit to the examination on oath by the treasurer as he or she deems necessary for the verification of the truth of the statement. Interest on the vessels and extraordinary repairs shall not be deducted from the earnings in making up the statement; and the owners shall pay to the town treasurer for the use of the town a tax of one percent (1%) on the net earnings; and in case the owners make the return and pay the tax provided in this section, they are subject to no other taxation on the property. Vessels are deemed to be engaged in foreign commerce in case three-fourths (3/4) of their earnings in any year have been received in foreign trade.
R.I. Gen. Laws § 44-5-25