A credit shall be granted against the tax imposed by this chapter with respect to a person’s use in this Commonwealth of a watercraft purchased by him in another state, or purchased by him in this Commonwealth if the state sales tax was paid thereon. The amount of the credit shall be equal to the tax paid by him to another state by reason of the imposition of a similar tax on his purchase or use of the property, or the sales tax paid to this Commonwealth. The amount of the credit shall not exceed the tax imposed by this chapter.