371 



where. This amendment eliminates the prohibited zone concept, which dis- 

 courages but does not prohibit indiscriminate discharge in the open sea beyond 

 the established prohibited zones (generally within 50 miles of land). Under the 

 1969 amendment and the proposed legislation, discharges of oil or oily mixtures 

 from ships to which the present International Convention applies, other than 

 tankers, will be prohibited unless : 



(1) The tanker is proceeding en route ; and 



(2) Tlie instantaneous rate of discharge of oil content does not exceed 60 

 litres per mile ; and 



(3) The oil content of the discharge is less than 100 parts per 1,000,000 parts 

 (ppm) of the mixture ; and 



(4) The ship is as far as practicable from land. 

 For tankers, all discharges are prohibited unless : 



(1) The tanker is proceeding en route ; and 



(2) The instantaneous rate of discharge of oil content does not exceed 60 

 litres per mile : and 



(3) The total quantity of oil discharged on a ballast voyage does not exceed 

 1/15,000 of the total cargo-carrying capacity ; and 



(4) The tanker is more than 50 miles from the nearest land. 



Under this proposed legislation, instantaneous rate of discharge of oil con- 

 tent is defined as the rate of discharge of oil in litres per hour at any instant 

 divided by the speed of the ship in knots at the same instant. Also, oily mixture 

 is redefined as a mixture mth any oil content rather than the present definition 

 which requires over 100 ppm to qualify as an oily mixture. 



Proponed Oil Record Book 



Entries in the oil record book of a vessel shall be made on each occasion, on a 

 tank-to-tank basis, whenever any of the following takes place in the ship : 



(1) For tankers — 



(a) Loading of oil cargo; 



(b) Transfer of oil cargo during voyage ; 



(c) Discharge of oil cargo; 



(d) Ballasting of cargo tanks ; 



(e) Cleaning of cargo tanks ; 



(f ) Discharge of dirty ballast ; 



(g) Discharge of water from slop tanks ; 

 (h) Disposal of residues; 



(i) Discharge overboard of bilge water containing oil which has accumulated 

 in machinery spaces while in port, and the routine discharge at sea of bilge water 

 containing oil unless the latter has been entered in the appropriate log book. 



(2) For ships other than tankers — 



(a) Ballasting or cleaning of bunker fuel tanks ; 



(b) Discharge of dirty ballast or cleaning water from bunker fuel tanks; 



(c) Disposal of residues; 



(d) Discharge overboard of bilge water containing oil which has accumulated 

 in machinery spaces while in port, and the en route discharge at sea of bilge 

 water containing oil unless the latter has been entered in the appropriate log 

 book. 



Proposed Great Barrier Reef Controls 



Under one of the 1971 amendments, the Great Barrier Reef of Australia is 

 considered equivalent to a land area? thereby precluding discharges of oil and 

 oily mixture in proximity of the shelf. 



Proposed Tank Size/Arrangement Limitation 



The other 1971 amendment to the International Convention deals with tank 

 arrangements and limitations of tank size for new tank vessels. Under the 

 provisions of this portion of the bill, every tanker to which this Act applies 

 and built in the U.S. and for which the building contract is placed on or after the 

 effective date of this section shall be constructed in accordance with the pro- 

 visions of Annex C to the Convention relating to tank arrangement and limita- 

 tion of tank size. Every tanker to which this proposed Act applies and built in 

 the United States and for which the building contract is placed or the keel is 

 laid or is in a similar state of construction, before the effective date of this 

 .section, shall, within two years after that date, comply with the provisions of 

 Annex C to the Convention if the delivery of the tanker is after 1 January 1977 ; 

 or if the delivery of the tanker is not later than 1 January 1977 and the building 



