46 CFR § 171.109 - Watertight floors in double bottoms.

---
identifier: "/us/cfr/t46/s171.109"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 171.109 - Watertight floors in double bottoms."
title_number: 46
title_name: "Shipping"
section_number: "171.109"
section_name: "Watertight floors in double bottoms."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "S"
subchapter_name: "SUBDIVISION AND STABILITY"
part_number: "171"
part_name: "SPECIAL RULES PERTAINING TO VESSELS CARRYING PASSENGERS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "46 U.S.C. 2103, 3306; E.O. 12234, 45 FR 58801, 3 CFR, 1980 Comp., p. 277; Department of Homeland Security Delegation No. 0170.1."
regulatory_source: "CGD 79-023, 48 FR 51017, Nov. 4, 1983, unless otherwise noted."
cfr_part: "171"
---


# 171.109 Watertight floors in double bottoms.

If a vessel is required to have a double bottom, a watertight transverse division must be located in the double bottom under each main transverse watertight bulkhead or as near as practicable to the main transverse watertight bulkhead. If a vessel also has duct keels, the transverse divisions need not extend across them.