15. The Trustees may borrow temporarily by way of overdraft or otherwise such sums of money as the Trustees may require for the purposes of meeting their obligations in carrying out their functions as harbour Trustees, but such sums shall not exceed £70,000 (or that sum as adjusted in accordance with paragraph 15(1) and (2).
(1) On each anniversary of the coming into force of this Act, the sums mentioned in articles 14 (1) and 15 above, shall be adjusted in line with any movement (calculated to one decimal place) in R.P.I. which occurred during the year ended on 31st December immediately preceding the anniversary in question.
(2) Any adjustment referred to in paragraph (1) shall be recorded in the next following annual statement of accounts prepared by the Trustees. In paragraph (1) above R.P.I. means the general index of retail prices for all items published in the monthly publication of the Office for National Statistics known as “Monthly Digest of Statistics” or any successor from time to time of that index.