buoyancy, or 12 per cent of the freeboard required for the flushdecked vessel after correction for length;

of the length of the vessel, deduct 8 per cent of the reserve buoyancy, or 10 per cent of the freeboard required for the vessel flush-decked after correction for length;

of the length of the vessel, deduct 6 per cent of the reserve buoyancy, or 8 per cent of the freeboard required for the vessel flush-decked after correction for length;

of the length of the vessel, deduct 4 per cent of the reserve buoyancy, or 6 per cent of the freeboard required for the flush-decked vessel after correction for length. In cases where less than of the length of the vessel is covered by erections, the allowance should be in proportion to that given for erections covering

of the length.

17. When a sailing vessel is fitted with a top-gallant forecastle only, the reduction in reserve buoyancy should be one-half that prescribed by the previous paragraph for the case where, in addition to the forecastle, the vessel is fitted with a poop of the same length. When there is a poop only, the allowance is to be half of that which in this paragraph is given for a forecastle only of the same length.

18. SHEER. The tables are framed for vessels having a mean sheer of deck measured at the side, as shown in the following table:

Flush-deck Vessels.-Sheer to be measured abreast stem and sternpost...

Vessels having short poops and forecastles.-Sheer to be measured at points distant the length

LENGTH OVER WHICH SHEER
IS MEASURED.

100 150 200 250 300 350 400

Mean Sheer in Inches Over the
Length Specified.

20 25 30 35 40 45 50

of the vessel from each end..... 14 18 22 26 30 34

Vessels having short forecastles only.-Sheer to be measured abreast the sternpost and at a point distant the length from the stem..

38

14 18 23 27 31 35 40

(a) In flush-deck vessels and in vessels to which paras. 11 and 12 apply, when the sheer of deck is greater or less than the above and is of a gradual character, divide the difference in inches between it and the mean sheer provided for by 4 and the result in inches is the amount by which the freeboard amidships should be diminished or increased according as the sheer is greater or less. (b) In vessels having short poops and forecastles, and in those having short forecastles only, the freeboard should be corrected in respect of the excess or deficiency in reserve buoyancy due to variations in sheer from the standard amount over the length uncovered by substantial erections, as provided in the above table. One-fourth the difference between the mean sheer specified and that measured as described is approximately the amount by which the freeboard should be modified in respect of sheer.

(c) The divisor 4 is to be used when the sheer is of a gradual character, and is not strictly applicable either to those cases in which the sheer is suddenly increased at the bow or stern, or to those in which it does not maintain its normal rate of increase to the ends of the vessel.

(d) In all cases the rise in sheer forward and aft is measured with reference to the deck at the middle of the length, and where the lowest point of the sheer is abaft the middle of the length, one-half the difference between the sheer amidships and the lowest point should be added to the freeboard specified in the tables for flush-deck vessels and for vessels having short poops and forecastles only.

(e) Where, as in some instances, vessels fitted with long poops or raised quarter-decks connected with bridge-houses have the deck line rising rapidly from amidships to the front of the bridge, and from that point onwards gradually approaching the normal sheer line, the freeboard may be slightly modified in consideration of the increase of height of deck in the "well."

(f) In flush-deck vessels and in vessels having short poops and forecastles the excess of sheer for which an allowance is made shall not exceed one-half the total standard mean sheer for the size of the ship.

(g) No decrease should be made in the freeboard of spar- and awning-deck vessels, in respect of excess of sheer.

19. ROUND OF BEAM. In calculating the reserve of buoyancy an allowance has been made of one-quarter of an inch for every foot of the length of the midship beam for the round up. When the round of the beam in flush-decked vessels is greater than given by this rule divide the difference in inches by 2 and diminish or increase the freeboard by this amount. For vessels with erections on deck the amount of the allowance