The recommendations in this document supplement U.S. Coast Guard regulations concerning marine vapor control systems@ contained in Title 33@ Code of Federal Regulations@ Parts 154-156 and Title 46@ Code of Federal Regulations@ Parts 30@ 32@ 35@ and 39. This recommended practice is intended for use for all vessels and terminals required to install vapor collection systems. The recommendations cover all vessel and barge size categories; however@ it is recognized that the application of the proposed piping arrangements and manifold spacings aboard existing vessels may be difficult or impossible due to space limitations. In such cases provisions for alternate vapor line locations are included in 2.2.3.2 for tank ships and 3.2.1 through 3.2.3 for tank barges. This recommended practice is patterned after@ and should be used in conjunction with@ the Oil Companies' International Marine Forum (OCIMF)@ Standards for Oil Tanker Manifolds and Associated Equipment@ Third Edition@ 1988. Specialized tank ships and barges@ particularly those employed in chemical and specialty product trades@ may require special manifold arrangements. Those arrangements are not addressed in this recommended practice. This recommended practice does not cover necessary safeguards to prevent or control releases@ fire@ or explosion in vapor control systems.