46 CFR § 39.2003 - Cargo gauging system—TB/ALL.

---
identifier: "/us/cfr/t46/s39.2003"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 39.2003 - Cargo gauging system—TB/ALL."
title_number: 46
title_name: "Shipping"
section_number: "39.2003"
section_name: "Cargo gauging system—TB/ALL."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "D"
subchapter_name: "TANK VESSELS"
part_number: "39"
part_name: "VAPOR CONTROL SYSTEMS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7511b(f)(2); 46 U.S.C. 3306, 3703, 3715(b), 70011, 70034; Executive Order 12234, 45 FR 58801, 3 CFR, 1980 Comp., p. 277; DHS Delegation No. 00170.1, Revision No. 01.4."
regulatory_source: "USCG-1999-5150, 78 FR 42642, July 16, 2013, unless otherwise noted."
cfr_part: "39"
---


# 39.2003 Cargo gauging system—TB/ALL.

(a) A cargo tank of the tank vessel connected to a vapor collection system must be equipped with a permanent or portable cargo gauging device that—

(1) Is a closed type as defined in 46 CFR 151.15.10(c) that does not require opening the tank to the atmosphere during cargo transfer;

(2) Allows the operator to determine the level of liquid in the tank for the full range of liquid levels in the tank;

(3) Has an indicator for the level of liquid in the tank that is located where cargo transfer is controlled; and

(4) If portable, is installed on the tank during the entire transfer operation.

(b) Each cargo tank of a tank barge must have a high-level indicating device, unless the barge complies with 46 CFR 39.2009(a). The high-level indicating device must—

(1) Indicate visually the level of liquid in the cargo tank when the liquid level is within a range of 1 meter (3.28 feet) of the top of the tank;

(2) Show a permanent mark to indicate the maximum liquid level permitted under 46 CFR 39.3001(e) at even keel conditions; and

(3) Be visible from all cargo control areas.