20. Entries shall be made in a book retained on board to record the following—
(1) the times of the last closing, before the ship proceeds on any voyage, of the closing appliances referred to in regulation 16(1) and of the next opening of such closing appliances;
(2) the times when the portable plates referred to in regulation 16(3) are fitted in place and the times of any removal and replacement of such plates whilst the ship is on any voyage; and
(3) the occasions on which drills are held and inspections made in compliance with these Regulations and whether or not the closing appliances and devices to which any such drill or inspection relates are in good working order when the drill or inspection takes place.