Home › CFR › Title 46 › Part 39346 CFR Part 393 — America's Marine Highway ProgramSubpart A — General Provisions§ 393.1— Special definitions.Subpart B — Marine Highway Route and Project Designations§ 393.2— Marine Highway Routes.§ 393.3— Marine Highway Projects.Subpart C — Department of Transportation Efforts To Foster and Support America's Marine Highways§ 393.4— DOT Support for planning activities.§ 393.5— DOT Support for Marine Highway-related research.§ 393.6— America's Marine Highway Program Project grants.