StacksVerified U.S. regulatory reference

46 CFR §174.207

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)Extent of damage. Damage must consist of penetrations having the dimensions specified by table 174.207(a) of this section, except that, if the most disabling penetrations are smaller than the penetrations specified by the table, damage must consist of the smaller penetrations.
  2. (b)Permeability of spaces. The permeability of a floodable space must be as specified by Table 174.207(b) of this section.
  3. (c)Survival conditions. An OSV is presumed to survive assumed damage if it meets the following conditions in the final stage of flooding:
    1. (1)Final waterline. The final waterline, in the final stage of sinkage, heel, and trim, must be below the lower edge of an opening through which progressive flooding may take place, such as an air pipe, a tonnage opening, an opening closed by a weathertight door or hatch-cover, or a tank vent fitted with a ball check-valve. This opening does not include an opening closed by a—
      1. (i)Watertight manhole-cover;
      2. (ii)Flush scuttle;
      3. (iii)Small hatch-cover for a watertight cargo-tank that maintains the high integrity of the deck;
      4. (iv)Watertight door in compliance with § 174.210 of this subpart; or
      5. (v)Side scuttle of the non-opening type.
    2. (2)Angle of heel. The angle of heel must not exceed 15 degrees.
    3. (3)Range of stability. Through an angle of 20 degrees beyond its position of equilibrium after flooding, an OSV must meet the following conditions:
      1. (i)The righting arm curve must be positive.
      2. (ii)The righting arm must be at least 100 millimeters (4 inches).
      3. (iii)Each submerged opening must be weathertight. (A tank vent fitted with a ball check-valve is weathertight.)
    4. (4)Progressive flooding. Piping, ducts, or tunnels within the assumed extent of damage must be either—
      1. (i)Equipped with arrangements, such as stop check-valves, to prevent progressive flooding of the spaces with which they connect; or
      2. (ii)Assumed in the calculations required by paragraph (a) of this section to permit progressive flooding of the spaces with which they connect.
  4. (d)Buoyancy of superstructure. For paragraph (a) of this section, the buoyancy of any superstructure directly above the side damage must be considered in the most unfavorable condition.