46 CFR § 169.231 - Definitions relating to hull examinations.
---
identifier: "/us/cfr/t46/s169.231"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 169.231 - Definitions relating to hull examinations."
title_number: 46
title_name: "Shipping"
section_number: "169.231"
section_name: "Definitions relating to hull examinations."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "R"
subchapter_name: "NAUTICAL SCHOOLS"
part_number: "169"
part_name: "SAILING SCHOOL VESSELS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "33 U.S.C. 1321(j); 46 U.S.C. 3306, 6101; Pub. L. 103-206, 107 Stat. 2439; E.O. 11735, 38 FR 21243, 3 CFR, 1971-1975 Comp., p. 793; DHS Delegation 00170.1, Revision No. 01.4; § 169.117 also issued under the authority of 44 U.S.C. 3507."
regulatory_source: "CGD 83-005, 51 FR 896, Jan. 9, 1986, unless otherwise noted."
cfr_part: "169"
---
# 169.231 Definitions relating to hull examinations.
As used in the part—
(a) *Drydock examination* means hauling out a vessel or placing a vessel in a drydock or slipway for an examination of all accessible parts of the vessel's underwater body and all through-hull fittings, sea chests, sea valves, sea strainers, and valves for the emergency bilge suction.
(b) *Underwater survey* means the examination of the vessel's underwater hull including all through-hull fittings and appurtenances, while the vessel is afloat.
(c) *Internal structural examination* means an examination of the vessel while afloat or in drydock and consists of a complete examination of the vessel's main strength members, including the major internal framing, the hull plating, voids, and ballast tanks, but not including cargo or fuel oil tanks.
[CGD 84-024, 52 FR 39656, Oct. 23, 1987, as amended at 53 FR 32232, Aug. 24, 1988; USCG-2000-6858, 67 FR 21084, Apr. 29, 2002]