(a) A Type “A” vessel is assigned a freeboard not less than that based on table 42.20-15(a)(1) provided that the vessel meets the flooding standard in § 42.20-6.

(b) A vessel that meets the requirements of subpart D, F, or G of part 172 of this chapter is considered by the Coast Guard as meeting the flooding standard referenced in paragraph (a) of this section.

[CGD 79-153, 48 FR 38647, Aug. 25, 1983, as amended by CGD 79-023, 49 FR 26593, June 28, 1984]

(a) Each Type “B” vessel is assigned a freeboard from table 42.20-15(b)(1) that is increased or decreased by the provisions of this section.

(b) Each Type “B” vessel that has a hatchway in position 1, must have the freeboard assigned in accordance with paragraph (a) of this section increased by the amount given in table 42.20-5(b) unless the hatch cover complies with:

(1) Section 42.15-25(d); or

(2) Section 42.15-30.

(c) Any Type “B” vessel that is greater than 100 meters (328 feet) in length and any hopper dredge meeting the requirements in subpart C of part 44 of this chapter may have a reduced freeboard from that assigned under table 42.20-15(b)(1) in accordance with paragraph (d) or paragraph (e) of this section if—

(1) The measures provided for the protection of the crew are adequate;

(2) The freeing arrangements are adequate; and

(3) The hatchway covers in positions 1 and 2 comply with the provisions of § 42.15-30 and have adequate strength, special care being given to their sealing and securing arrangements.

(d) The freeboards for a Type “B” vessel which comply with paragraph (c) of this section may be reduced up to 60 percent of the total difference between the freeboards in table 42.20-15(b)(1) and table 42.20-15(a)(1) provided that the vessel meets the flooding standard in § 42.20-7.

(e) The freeboards for a Type “B” vessel which complies with paragraph (c) of this section may be reduced up to the total difference between the freeboard tables referenced in paragraph (d) of this section provided that the vessel meets the flooding standard in § 42.20-8 and the provisions of § 42.15-80 (a), (b) and (d) as if it were a Type “A” vessel.

[CGD 79-153, 48 FR 38647, Aug. 25, 1983, as amended by CGD 76-080, 54 FR 36976, Sept. 6, 1989]

(a) Design calculations must be submitted that demonstrate that the vessel will remain afloat in the conditions of equilibrium specified in § 42.20-12 assuming the damage specified in § 42.20-11 as applied to the following flooding standards:

(1) If the vessel is over 150 meters (492 feet) in length it must be able to withstand the flooding of any one compartment, except the machinery space.

(2) If the vessel is over 225 meters (738 feet) in length, it must be able to withstand the flooding of any one compartment, treating the machinery space as a floodable compartment.

(b) When doing the calculations required in paragraph (a) of this section, the following permeabilities must be assumed:

(1) 0.95 in all locations except the machinery space.

(2) 0.85 in the machinery space.

[CGD 79-153, 48 FR 38648, Aug. 25, 1983]

(a) Design calculations must be submitted that demonstrate that the vessel will remain afloat in the conditions of equilibrium specified in § 42.20-12 assuming the damage specified in § 42.20-11 as applied to the following flooding standards:

(1) If the vessel is 225 meters (738 feet) or less in length, it must be able to withstand the flooding of any one compartment, except the machinery space.

(2) If the vessel is over 225 meters (738 feet) in length, it must be able to withstand the flooding of any one compartment, treating the machinery space as a floodable compartment.

(b) When doing the calculations required in paragraph (a) of this section, the following permeabilities must be assumed:

(1) 0.95 in all locations except the machinery space.

(2) 0.85 in the machinery space.

[CGD 79-153, 48 FR 38648, Aug. 25, 1983]

(a) Design calculations must be submitted that demonstrate that the vessel will remain afloat in the conditions of equilibrium specified in § 42.20-12 assuming the damage specified in § 42.20-11 as applied to the following flooding standards:

(1) If the vessel is 225 meters (738 feet) or less in length, it must be able to withstand the flooding of any two adjacent fore and after compartments excluding the machinery space;

(2) If the vessel is over 225 meters (738 feet) in length, the flooding standard of paragraph (a)(1) of this section must be applied, treating the machinery space, taken alone, as a floodable compartment.

(b) When doing the calculations required in paragraph (a) of this section, the following permeabilities must be assumed:

(1) 0.95 in all locations except the machinery space.

(2) 0.85 in the machinery space.

[CGD 79-153, 48 FR 38648, Aug. 25, 1983]

When doing the calculations required in §§ 42.20-6(a), 42.20-7(a) and 42.20-8(a), the initial condition of loading before flooding must be assumed to be as specified in this section:

(a) The vessel is assumed to be loaded to its summer load waterline with no trim.

(b) When calculating the vertical center of gravity, the following assumptions apply:

(1) The cargo is assumed to be homogeneous.

(2) Except as specified in paragraph (b)(3) of this section, all cargo compartments are assumed to be fully loaded. This includes compartments intended to be only partially filled. In the case of liquid cargoes, fully loaded means 98 percent full.

(3) If the vessel is intended to operate at its summer load waterline with empty compartments, these empty compartments are assumed to be empty rather than fully loaded if the resulting height of the vertical center of gravity is not less than the height determined in accordance with paragraph (b)(2) of this section.

(4) Fifty percent of the total capacity of all tanks and spaces fitted to contain consumable liquids or stores must be assumed to be distributed to accomplish the following:

(i) Each tank and space fitted to contain consumable liquids or stores must be assumed either completely empty or completely filled.

(ii) The consumables must be distributed so as to produce the greatest possible height above the keel for the center of gravity.

(5) Weights are calculated using the following values for specific gravities:

Salt water—1.025 Fresh water—1.000 Oil fuel—0.950 Diesel oil—0.900 Lube oil—0.900 [CGD 79-153, 48 FR 38648, Aug. 25, 1983]

When doing the calculations required in §§ 42.20-6(a), 42.20-7(a) and 42.20-8(a), the effect of free surface of the following liquids must be included:

(a) For each type of consumable liquid, the maximum free surface of at least one transverse pair of tanks or a single centerline tank must be included. The tank or combination of tanks must be that resulting in the greatest free surface effect.

(b) For cargo liquids, unless the compartment is assumed to be empty as required by § 42.20-9(b)(3), the free surface of those compartments containing liquids is calculated at an angle of heel of not more than 5 degrees.

[CGD 79-153, 48 FR 38649, Aug. 25, 1983]

When doing the calculations required by §§ 42.20-6(a), 42.20-7(a) and 42.20-8(a), the following must be assumed:

(a) The vertical extent of damage in all cases must be assumed to be from the baseline upward without limit.

(b) The transverse extent of damage is assumed to be equal to B/5 or 11.5 meters (37.7 feet), whichever is less. The transverse extent is measured inboard from the side of the ship perpendicularly to the center line at the level of the summer load waterline.

(c) If damage of a lesser extent than that specified in paragraph (a) or (b) of this section results in a more severe condition, the lesser extent must be assumed.

(d) The following assumptions apply to the transverse damage specified in paragraph (b) of this section for a stepped or recessed bulkhead:

(1) A transverse watertight bulkhead that has a step or recess located within the transverse extent of assumed damage may be considered intact if the step or recess is not more than 3.05 meters (10 feet) in length.

(2) If a transverse watertight bulkhead has a step or recess of more than 3.05 meters (10 feet) in length, within the transverse extent of assumed damage, the two compartments adjacent to this bulkhead must be considered as flooded.

(3) If within the transverse extent of damage, a transverse bulkhead has a step or recess more than 3.05 meters (10 feet) in length that coincides with the double bottom tank top or the inner boundary of a wing tank, respectively, all adjacent compartments within the transverse extent of assumed damage must be considered to be flooded simultaneously.

(e) If a wing tank has openings into adjacent compartments, the wing tank and adjacent compartments must be considered as one compartment. This provision applies even where these openings are fitted with closing appliances except:

(1) Valves fitted in bulkheads between tanks which are controlled from above the bulkhead deck.

(2) Secured manhole covers fitted with closely spaced bolts.

(f) Only transverse watertight bulkheads that are spaced apart at least 1/3(L) 2/3 or 14.5 meters (0.495(L) 2/3 or 47.6 feet), whichever is less, may be considered effective. If transverse bulkheads are closer together, then one or more of these bulkheads must be assumed to be non-existent in order to achieve the minimum spacing between bulkheads.

[CGD 79-153, 48 span 38649, Aug. 25, 1983]

The following conditions of equilibrium are regarded as satisfactory:

(a) Downflooding. The final waterline after flooding, taking into account sinkage, heel, and trim, is below the lower edge of any opening through which progressive flooding can take place. Such openings include air pipes, ventilators, and openings which are closed by means of weathertight doors (even if they comply with § 42.15-10) or covers (even if they comply with § 42.15-30 or § 42.15-45(d)) but may exclude those openings closed by means of:

(1) Manhole covers and flush scuttles which comply with § 42.15-40;

(2) Cargo hatch covers which comply with § 42.09-5(b);

(3) Hinged watertight doors in an approved position which are secured closed while at sea and so logged; and

(4) Remotely operated sliding watertight doors, and side scuttles of the non-opening type which comply with § 42.15-65.

(b) Progressive flooding. If pipes, ducts, or tunnels are situated within the assumed extent of damage penetration as defined in § 42.20-11 (a) and (b), progressive flooding cannot extend to compartments other than those assumed to be floodable in the calculation for each case of damage.

(c) Final angle of heel. The angle of heel due to unsymmetrical flooding does not exceed 15 degrees. If no part of the deck is immersed, an angle of heel of up to 17 degrees may be accepted.

(d) Metacentric height. The metacentric height of the damaged vessel, in the upright condition, is positive.

(e) Residual stability. Through an angle of 20 degrees beyond its position of equilibrium, the vessel must meet the following conditions:

(1) The righting arm must be positive.

(2) The maximum righting arm must be at least 0.1 meter (4 inches).

(3) The area under the righting arm curve within the 20 degree range must not be less than 0.0175 meter-radians (0.689 inch-radians).

(4) Each submerged opening must be weathertight (e.g. a vent fitted with a ball check valve).

(f) Intermediate stages of flooding. The Commandant is satisfied that the stability is sufficient during intermediate stages of flooding.

[CGD 79-153, 48 FR 38649, Aug. 25, 1983]

(a) A lighter, barge, or other vessel without independent means of propulsion is assigned a freeboard in accordance with the provisions of this subpart as modified by paragraphs (b), (c), and (d) of this section.

(b) A barge that meets the requirements of § 42.09-5(b) may be assigned Type “A” freeboard if the barge does not carry deck cargo.

(c) An unmanned barge is not required to comply with § 42.15-75, § 42.15-80(b), or § 42.20-70.

(d) An unmanned barge that has only small access openings closed by watertight gasketed covers of steel or equivalent material on the freeboard deck, may be assigned a freeboard 25 percent less than that calculated in accordance with this subpart.

[CGD 79-153, 48 FR 38649, Aug. 25, 1983]

(a) Type “A” vessel. (1) The tabular freeboard for Type “A” vessel shall be determined from table 42.20-15(a)(1):

(b) Type “B” vessels. (1) The tabular freeboard for Type “B” vessels shall be determined from table 42.20-15(b)(1):

[CGFR 68-60, 33 FR 10064, July 12, 1968, as amended by CGFR 68-126, 34 FR 9015, June 5, 1969]

(a) The tabular freeboard for a Type “B” vessel of between 79 feet and 328 feet in length having enclosed superstructures with an effective length of up to 35 percent of the length of the vessel shall be increased by:

0.09 (328−L) [0.35−(E/L)] inches where: L = length of vessel in feet. E = effective length of superstructure in feet as defined in § 42.20-50. [CGFR 68-60, 33 FR 10064, July 12, 1968]

If the block coefficient (Cb) exceeds 0.68, the tabular freeboard specified in § 42.20-15 as modified, if applicable, by §§ 42.20-5 (b) and (d), and 42.20-20(a) must be multiplied by the factor (Cb + 0.68)/1.36.

[CGD 79-153, 48 FR 38650, Aug. 25, 1983]

(a) Where D exceeds L 1/15 the freeboard shall be increased by [D−(L/15)] R inches, where R is L/131.2 at lengths less than 393.6 feet and 3 at 393.6 feet length and above.

(b) Where D is less than L/15 no reduction shall be made except in a vessel with an enclosed superstructure covering at least 0.6L amidships, with a complete trunk, or combination of detached enclosed superstructures and trunks which extend all fore and aft, where the freeboard shall be reduced at the rate prescribed in paragraph (a) of this section.

(c) Where the height of superstructure or trunk is less than the standard height, the reduction shall be in the ratio of the actual to the standard height as defined in § 42.20-40.

[CGspan 68-60, 33 span 10064, July 12, 1968]

(a) Where the actual depth to the upper edge of the deck line is greater or less than D, the difference between the depths shall be added to or deducted from the freeboard.

[CGFR 68-60, 33 FR 10065, July 12, 1968]

(a) The standard height of a superstructure shall be as given in table 42.20-40(a):

[CGFR 68-60, 33 FR 10065, July 12, 1968, as amended by CGFR 68-126, 34 FR 9015, June 5, 1969]

(a) Except as provided in paragraph (b) of this section, the length of a superstructure (S) shall be the mean length of the parts of the superstructure which lie within the length (L).

(b) Where the end bulkhead of an enclosed superstructure extends in a fair convex curve beyond its intersection with the superstructure sides, the length of the superstructure may be increased on the basis of an equivalent plane bulkhead. This increase shall be two-thirds of the fore and aft extent of curvature. The maximum curvature which may be taken into account in determining this increase is one-half the breadth of the superstructure at the point of intersection of the curved end of the superstructure with its side.

[CGFR 68-60, 33 FR 10065, July 12, 1968, as amended by CGFR 68-126, 34 FR 9015, June 5, 1969]

(a) Except as provided for in paragraph (b) of this section the effective length (E) of an enclosed superstructure of standard height shall be its length.

(b) In all cases where an enclosed superstructure of standard height is set in from the sides of the vessel as permitted in § 42.13-15(j), the effective length shall be the length modified by the ratio of b/Bs,

where: “b” is the breadth of the superstructure at the middle of its length; “Bs” is the breadth of the vessel at the middle of the length of the superstructure.

(1) Where a superstructure is set in for a part of its length, this modification shall be applied only to the set in part.

(c) Where the height of an enclosed superstructure is less than the standard height, the effective length shall be its length reduced in the ratio of the actual height to the standard height. Where the height exceeds the standard, no increase shall be made to the effective length of the superstructure.

(d) The effective length of a raised quarter deck if fitted with an intact front bulkhead, shall be its length up to a maximum of 0.6L. Where the bulkhead is not intact, the raised quarter deck shall be treated as a poop of less than standard height.

(e) Superstructures which are not enclosed shall have no effective length.

[CGFR 68-60, 33 FR 10065, July 12, 1968]

(a) A trunk or similar structure which does not extend to the sides of the vessel shall be regarded as efficient on the following conditions:

(1) The trunk is at least as strong as a superstructure;

(2) The hatchways are in the trunk deck, and the hatchway coamings and covers comply with the requirements of §§ 42.15-15 to 42.15-30, inclusive, and the width of the trunk deck stringer provides a satisfactory gangway and sufficient lateral stiffness; however, small access openings with watertight covers may be permitted in the freeboard deck;

(3) A permanent working platform fore and aft fitted with guard rails is provided by the trunk deck, or by detached trunks connected to superstructures by efficient permanent gangways;

(4) Ventilators are protected by the trunk by watertight covers or by other equivalent means;

(5) Open rails are fitted on the weather parts of the freeboard deck in way of the trunk for at least half their length;

(6) The machinery casings are protected by the trunk, by a superstructure of at least standard height, or by a deckhouse of the same height and of equivalent strength;

(7) The breadth of the trunk is at least 60 percent of the breadth of the vessel; and,

(8) Where there is no superstructure, the length of the trunk is at least 0.6L.

(b) The full length of an efficient trunk reduced in the ratio of its mean breadth to B shall be its effective length.

(c) The standard height of a trunk is the standard height of a superstructure other than a raised quarter deck.

(d) Where the height of a trunk is less than the standard height, its effective length shall be reduced in the ratio of the actual to the standard height. Where the height of hatchway coamings on the trunk deck is less than that required under § 42.15-25(a), a reduction from the actual height of trunk shall be made which corresponds to the difference between the actual and required height of coaming.

[CGFR 68-60, 33 FR 10065, July 12, 1968, as amended by CGFR 68-126, 34 FR 9015, June 5, 1969]

(a) Where the effective length of superstructures and trunks is 1.0L, the deduction from the freeboard shall be 14 inches at 79 feet length of vessel, 34 inches at 279 feet length, and 42 inches at 400 feet length and above; deductions at intermediate lengths shall be obtained by linear interpolation.

(b) Where the total effective length of superstructures and trunks is less than 1.0L the deduction shall be a percentage obtained from table 42.20-60(b)(1) or table 42.20-60(b)(2):

(c) For vessels of Type “B”:

(1) Where the effective length of a bridge is less than 0.2L, the percentages shall be obtained by linear interpolation between lines I and II;

(2) Where the effective length of a forecastle is more than 0.4L, the percentages shall be obtained from line II; and,

(3) Where the effective length of a forecastle is less than 0.07L, the percentages in table 42.20-60(b)(2) of this paragraph shall be reduced by:

5(0.07L−f)/0.07L L is the length of vessel as defined in § 42.13-15(a), f is the effective length of the forecastle. [CGFR 68-60, 33 FR 10065, July 12, 1968, as amended by CGFR 68-126, 34 FR 9015, June 5, 1969; USCG-2014-0688, 79 FR 58280, Sept. 29, 2014]

(a) General. (1) The sheer shall be measured from the deck at side to a line of reference drawn parallel to the keel through the sheer line amidships.

(2) In vessels designed with a rake of keel, the sheer shall be measured in relation to a reference line drawn parallel to the design load waterline.

(3) In flush deck vessels and in vessels with detached superstructures the sheer shall be measured at the freeboard deck.

(4) In vessels with topsides of unusual form in which there is a step or break in the topsides, the sheer shall be considered in relation to the equivalent depth amidships.

(5) In vessels with a superstructure of standard height which extends over the whole length of the freeboard deck, the sheer shall be measured at the superstructure deck. Where the height exceeds the standard the least difference (Z) between the actual and standard heights shall be added to each end ordinate. Similarly, the intermediate ordinates at distances of 1/6L and 1/3L from each perpendicular shall be increased by 0.444Z and 0.111Z respectively.

(6) Where the deck of an enclosed superstructure has at least the same sheer as the exposed freeboard deck, the sheer of the enclosed portion of the freeboard deck shall not be taken into account.

(7) Where an enclosed poop or forecastle is of standard height with greater sheer than that of the freeboard deck, or is of more than standard height, an addition to the sheer of the freeboard deck shall be made as provided in paragraph (c)(4) of this section.

(b) Standard sheer profile. (1) The ordinates of the standard sheer profile are given in table 42.20-65(b)(1):

(c) Measurement of variation from standard sheer profile. (1) Where the sheer profile differs from the standard, the four ordinates of each profile in the forward or after half shall be multiplied by the appropriate factors given in the table of ordinates. The difference between the sums of the respective products and those of the standard divided by 8 measures the deficiency or excess of sheer in the forward or after half. The arithmetical mean of the excess or deficiency in the forward and after halves measures the excess or deficiency of sheer.

(2) Where the after half of the sheer has an excess and the forward half of the sheer has a deficiency, no credit shall be allowed for the part in excess and deficiency only shall be measured.

(3) Where the forward half of the sheer profile exceeds the standard, and the after portion of the sheer profile is not less than 75 percent of the standard, credit shall be allowed for the part in excess; where the after part is less than 50 percent of the standard, no credit shall be given for the excess sheer forward. Where the after sheer is between 50 percent and 75 percent of the standard, intermediate allowances may be granted for excess sheer forward.

(4) Where sheer credit is given for a poop or forecastle, the following formula shall be used:

s = (y/3)(L′/L) where: s = sheer credit, to be deducted from the deficiency or added to the excess of sheer. y = difference between actual and standard height of superstructure at the end ordinate. L′ = mean enclosed length of poop or forecastle up to a maximum length of 0.5L. L = length of vessel as defined in § 42.13-15(a).

(i) The formula in this paragraph (c)(4) of this section provides a curve in the form of a parabola tangent to the actual sheer curve at the freeboard deck and intersecting the end ordinate at a point below the superstructure deck a distance equal to the standard height of a superstructure. The superstructure deck shall not be less than standard height above this curve at any point. This curve shall be used in determining the sheer profile for forward and after halves of the vessel.

(d) Correction for variations from standard sheer profile. (1) The correction for sheer shall be the deficiency or excess of sheer (see paragraphs (c) (1) to (4) inclusive of this section) multiplied by:

0.75−(S/2L) where: S is the total length of enclosed superstructures.

(e) Addition for deficiency in sheer. (1) Where the sheer is less than the standard, the correction for deficiency in sheer (see paragraph (d)(1) of this section) shall be added to the freeboard.

(f) Deduction for excess sheer. (1) In vessels where an enclosed superstructure covers 0.1L before and 0.1L abaft amidships, the correction for excess of sheer as calculated under the provisions of paragraph (d)(1) of this section shall be deducted from the freeboard; in vessels where no enclosed superstructure covers amidships, no deduction shall be made from the freeboard; where an enclosed superstructure covers less than 0.1L before and 0.1L abaft amidships, the deduction shall be obtained by linear interpolation. The maximum deduction for excess sheer shall be at the rate of 1 1/2 inches per 100 feet of length.

[CGspan 68-60, 33 span 10066, July 12, 1968, as amended by CGspan 68-126, 34 span 9016, June 5, 1969]

(a) The bow height defined as the vertical distance at the forward perpendicular between the waterline corresponding to the assigned summer freeboard and the designed trim and the top of the exposed deck at side shall be not less than:

(1) For vessels below 820 feet in length,

0.672L[1−(L/1640)][1.36/(Cb + 0.68)] inches; where: L is the length of the vessel in feet. Cb is the block coefficient which is to be taken as not less than 0.68.

(2) For vessels of 820 feet and above in length,

275.6[1.36/(Cb + 0.68)] inches; where: Cb is the block coefficient which is to be taken as not less than 0.68.

(b) Where the bow height required in paragraph (a) of this section is obtained by sheer, the sheer shall extend for at least 15 percent of the length of the vessel measured from the forward perpendicular. Where it is obtained by fitting a superstructure, such superstructure shall extend from the stem to a point at least 0.07L abaft the forward perpendicular, and it shall comply with the following requirements:

(1) For vessels not over 328 feet in length it shall be enclosed as defined in § 42.13-15(j); and,

(2) For vessels over 328 feet in length it need not comply with § 42.13-15(j) but shall be fitted with closing appliances to the satisfaction of the assigning authority.

(c) Vessels which, to suit exceptional operational requirements, cannot meet the requirements of paragraphs (a) and (b) of this section may be given special consideration by the assigning authority.

[CGFR 68-60, 33 FR 10066, July 12, 1968, as amended by CGFR 68-126, 34 FR 9016, June 5, 1969]

(a) Summer freeboard. (1) The minimum freeboard in summer must be the freeboard derived from the tables in § 42.20-15 as modified by the corrections in §§ 42.20-3 and 42.20-5, as applicable, and §§ 42.20-20, 42.20-25, 42.20-30, 42.20-35, 42.20-60, 42.20-65 and, if applicable, § 42.20-70.

(2) The freeboard in salt water, as calculated in accordance with paragraph (a)(1) of this section, but without the correction for deck line, as provided by § 42.20-35, shall not be less than 2 inches. For vessels having in position 1 hatchways with covers which do not comply with the requirements of §§ 42.15-25(d)(1), 42.15-30, or 42.15-80, the freeboard shall be not less than 6 inches.

(b) Tropical freeboard. (1) The minimum tropical freeboard shall be the freeboard obtained by a deduction from the summer freeboard of one forty-eighth of the summer draft measured from the top of the keel to the center of the ring of the load line mark.

(2) The freeboard in salt water, as calculated in accordance with paragraph (b)(1) of this section, but without the correction for deck line, as provided by § 42.20-35, shall not be less than 2 inches. For vessels having in position 1 hatchways with covers which do not comply with the requirements of § 42.15-25(d)(1), § 42.15-30, or § 42.15-80, the freeboard shall be not less than 6 inches.

(c) Winter freeboard. (1) The minimum winter freeboard shall be the freeboard obtained by an addition to the summer freeboard of one forty-eighth of summer draft, measured from the top of the keel to the center of the ring of the load line mark.

(d) Winter North Atlantic freeboard. (1) The minimum freeboard for vessels of not more than 328 feet in length which enter any part of the North Atlantic defined in § 42.30-35 during the winter seasonal period shall be the winter freeboard plus 2 inches. For other vessels the winter North Atlantic freeboard shall be the winter freeboard.

(e) Fresh water freeboard. (1) The minimum freeboard in fresh water of unit density shall be obtained by deducting from the minimum freeboard in salt water:

(Δ/40 T) inches where: Δ = displacement in salt water in tons at the summer load waterline; and, T = tons per inch immersion in salt water at the summer load waterline.

(2) Where the displacement at the summer load waterline cannot be certified, the deduction shall be one forty-eighth of summer draft, measured from the top of the keel to the center of the ring of the load line mark.

[CGFR 68-60, 33 FR 10066, July 12, 1968, as amended by CGFR 68-126, 34 FR 9016, June 5, 1969; CGD 79-153, 48 FR 38650, Aug. 25, 1983]