Home › CFR › Title 33 › Part 6433 CFR Part 64 — Marking of Structures, Sunken Vessels and Other ObstructionsSubpart A — General§ 64.01— Purpose.§ 64.03— Scope.§ 64.06— Definition of terms.Subpart B — Sunken Vessels and Other Obstructions§ 64.11— Marking, notification, and approval requirements.§ 64.13— Approval for waiver of markings.§ 64.16— Duration of marking on sunken vessels in navigable waters.Subpart C — Structures§ 64.21— Marking and notification requirements.§ 64.23— Duration of marking on structures.Subpart D — Miscellaneous Provisions§ 64.31— Determination of hazard to navigation.§ 64.33— Marking by the Coast Guard.