49 CFR § 850.5 - Definitions.

---
identifier: "/us/cfr/t49/s850.5"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 850.5 - Definitions."
title_number: 49
title_name: "Transportation"
section_number: "850.5"
section_name: "Definitions."
chapter_name: "NATIONAL TRANSPORTATION SAFETY BOARD"
part_number: "850"
part_name: "COAST GUARD—NATIONAL TRANSPORTATION SAFETY BOARD MARINE CASUALTY INVESTIGATIONS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "Sec. 304(a)(1)(E), Independent Safety Board Act of 1974, Pub. L. 93-633, 88 Stat. 2168 (49 U.S.C. 1903)."
regulatory_source: "42 FR 61204, Dec. 1, 1977, unless otherwise noted."
cfr_part: "850"
---


# 850.5 Definitions.

As used in this part:

(a) *Act* means Title III of Pub. L. 93-633, the Independent Safety Board Act of 1974 (49 U.S.C. 1901, *et seq.*).

(b) *Board* means the National Transportation Safety Board.

(c) *Chairman* means the Chairman of the National Transportation Safety Board.

(d) *Commandant* means the Commandant of the Coast Guard.

(e) *Major marine casualty* means a casualty involving a vessel, other than a public vessel, that results in—

(1) The loss of six or more lives;

(2) The loss of a mechanically propelled vessel of 100 or more gross tons;

(3) Property damage initially estimated as $500,000 or more; or

(4) Serious threat, as determined by the Commandant and concurred in by the Chairman, to life, property, or the environment by hazardous materials.

(f) *Public vessel* means a vessel owned by the United States, except a vessel to which the Act of October 25, 1919, c. 82 (41 Stat. 305, 46 U.S.C. 363) applies.

(g) *Vessel of the United States* means a vessel—

(1) Documented, or required to be documented, under the laws of the United States;

(2) Owned in the United States; or

(3) Owned by a citizen or resident of the United States and not registered under a foreign flag.