Oily Mixtures (“Oily Bilge Water”) Management for
Oceangoing Vessels of less than 400 Gross Tons1
Compliance Options – Retain onboard or discharge through an oily-water separator (OWS)
This bulletin summarizes key legal requirements in 33 CFR Part 151, Subpart A and 33 CFR Part 155, Subparts
A and B for the proper management and disposal of oily mixtures by oceangoing vessels under 400 gross tons. 2
An “oceangoing ship [or vessel]” – as defined in 33 CFR 151.05 – means any vessel that operates on international
voyages, is certified for coastwise service beyond three miles, or operates beyond three nautical miles at any time.
Oceangoing vessels falling into this category include – but are not limited to – tugs, ferries, shuttle vessels,
commercial fishing vessels, and tour boats.