TREATIES The buoyancy of a metal boat of this type shall not be less than that required above for a wooden boat of the same cubic capacity, the volume of watertight air-cases being increased accordingly. (b.) Lifeboats with Internal and External Buoyancy. Intbrnal and exter- The internal buoyancy of a wooden boat of this type shall be pro- nal buoyancy. vided by watertight air-cases, the total volume of which is at least equal to seven and a half per cent. of the cubic capacity of the boat. The external buoyancy may be of cork or of any other equally efficient material, but such buoyancy shall not be obtained by the use of rushes, cork shavings, loose granulated cork or any other loose granu- lated substance, or by any means dependent upon inflation by air. If the buoyancy is of cork, its volume, for a wooden boat, shall not be less than thirty-three thousandths of the cubic capacity of the boat; if of any material other than cork, its volume and distribution shall be such that the buoyancy and stability of the boat are not less than that of a similar boat provided with buoyancy of cork. The buoyancy of a metal boat shall be not less than that required above for a wooden boat of the same cubic capacity, the volume of the watertight air-cases and that of the external buoyancy being increased accordingly. REGULAION XXVI. Boats of Class II. Boats of Class II. Conditions. Boats of Class II must satisfy the following conditions:- (a.) Open Boats with Internal and Eternal Buoyancy-Upper Part of Sides collapsible. Open boats, etc. A boat of this type shall be fitted both with watertight air-cases and with external buoyancy the aggregate volume of which, for each person which the boat is able to accommodate, shall be at least equal to the following amounts:- Cubic Cubic. Decimetres. Feet. Air-cases . . .. . . . . . . . . . 43 1.5 External buoyancy (if of cork) . . . .. 6 0.2 The external buoyancy may be of cork or of any other equally efficient material, but such buoyancy shall not be obtained by the use of rushes, cork shavings, loose granulated cork, or any other loose granulated substance, or by any means dependent upon inflation by air.
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