New York Codes, Rules and Regulations
Title 21 - Miscellaneous
Chapter XVII - Albany Port District Commission
Part 800 - General Rules And Regulations
Section 800.32 - Control of smoke emissions from vessels

No person shall operate any combustion installation on any vessel as to produce or permit the escape of smoke regardless of how produced or discharged in any shade of great density darker than a No. 2 Ringlemann chart or an equivalent standard, except when building a new fire, tube blowing, preparation for sailing or when a breakdown of equipment occurs which makes it evident that the emission was not reasonably preventable; smoke which is not greater than a No. 3 Ringlemann chart or equivalent standard may be emitted for a period or periods not exceeding three minutes in any 30 minute period.