33 CFR § 169.10 - What geographic coordinates are used?

---
identifier: "/us/cfr/t33/s169.10"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "33 CFR § 169.10 - What geographic coordinates are used?"
title_number: 33
title_name: "Navigation and Navigable Waters"
section_number: "169.10"
section_name: "What geographic coordinates are used?"
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "P"
subchapter_name: "PORTS AND WATERWAYS SAFETY"
part_number: "169"
part_name: "SHIP REPORTING SYSTEMS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "46 U.S.C. 70005, 70034, 70115, Department of Homeland Security Delegation No. 0170.1."
regulatory_source: "USCG-1999-5525, 64 FR 29234, June 1, 1999, unless otherwise noted."
cfr_part: "169"
---


# 169.10 What geographic coordinates are used?

Geographic coordinates expressed in terms of latitude or longitude, or both, are not intended for plotting on maps or charts where the referenced horizontal datum is the North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly labeled NAD 83. Geographic coordinates without the NAD 83 reference may be plotted on maps or charts referenced to NAD 83 only after application of the appropriate corrections that are published on the particular map or chart being used.