46 C.F.R. § 171.109 Watertight floors in double bottoms.
Title 46 - Shipping
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.
Title 46: Shipping
PART 171—SPECIAL RULES PERTAINING TO VESSELS CARRYING PASSENGERS
Subpart D—Additional Subdivision Requirements
§ 171.109 Watertight floors in double bottoms.
