145 



5 



1 (B) by changing the semicolon to a period at the 



2 end of subsection (b) thereof; and 



3 (C) by repeahng subsection (c) thereof. 



4 (4) Section 5 (33 U.S.C. 1004) is amended to read 



5 as follows : 



6 "Sec. 5. Section 3 does not apply to the discharge of 



7 tanker ballast from a cargo tank which, since the cargo was 



8 last carried therein, has been so cleaned that any effluent 



9 therefrom, if it were discharged from a stationary tanker into 



10 clean calm water on a clear day, would produce no visible 



11 traces of oil on the surface of the water.". 



12 (5) Insert a new section 6, to read as follows, foUow- 



13 ing section 5: 



1^ "Sec. 6. (a) Every tanker to which this Act applies 



and built in the United States and for which the building 

 contract is placed on or after the effective date of this sec- 

 tion shall be constructed in accordance with the provisions 



■'° of Annex C to the convention, relating to tank arrangement 



^^ and limitation of tank size. 



^" "(b) Every tanker to which this Act applies and built 



in the United States and for 'which the building contract is- 



2^ placed, or in the absence of a building contract the keel of 



^^ which is laid or which is at a similar state of construction, 



^^ before the effective date of this section, shall, within two 



