26 U.S.C. § 1357: Items not subject to regular tax; depreciation; interest

Gross income of an electing corporation shall not include its income from qualifying shipping activities. Gross income of a corporation (other than an electing corporation) which is a member of an electing group shall not include its income from qualifying shipping activities conducted by such member. Subject to paragraph (2), each item of loss, deduction (other than for interest expense), or credit of any taxpayer with respect to any activity the income from which is excluded from gross income under this section shall be disallowed. Notwithstanding paragraph (1), the adjusted basis (for purposes of determining gain) of any qualifying vessel shall be determined as if the deduction for depreciation had been allowed. Except as provided in clause (ii), the straight-line method of depreciation shall apply to qualifying vessels the income from operation of which is excluded from gross income under this section. Clause (i) shall not apply to any qualifying vessel which is subject to a charter entered into before the date of the enactment of this subchapter. Except as provided in subparagraph (B), the interest expense of an electing corporation shall be disallowed in the ratio that the fair market value of such corporation’s qualifying vessels bears to the fair market value of such corporation’s total assets. In the case of a corporation which is a member of an electing group, the interest expense of such corporation shall be disallowed in the ratio that the fair market value of such corporation’s qualifying vessels bears to the fair market value of the electing groups total assets.