A race officer should be at his post _at least_ half an hour before the first race begins (Rule 1). This gives him only fifteen minutes to see that things are 'shipshape' before flag B is hoisted (Rule 17). During this time he must decide whether the regatta or any race must be postponed on account of bad weather, in which case letter N is hoisted over the flag denoting the race or races so postponed (Rule 2). He should discover from the secretary that the marks are all correctly moored, the flags and guns ready, and everything in order. It is a great convenience to sailing masters to have a _time gun_ fired half an hour before the start for the first race; but this should not be done unless it be mentioned on the race card. The race officer should time this gun to the fraction of a second, and start all the races in strict accordance therewith. The officer should also make himself acquainted with the racing colours (Rule 11), and, if possible, with any peculiarities in the appearance of the yachts which are about to compete, in order that they may be easily identified at the start. As the time for hoisting flag B (race 1) approaches, the officer should warn the man at the signal halliards, who will hoist the flag, _furled_, at the peak, and the instant the officer gives the time signal the flag should be 'broken out' by a sharp jerk on the halliard. As the time for _first gun_ approaches, the blue peter is hoisted similarly by another halliard, and is 'broken out' the instant the officer gives the time signal; the gun is fired simultaneously, and should it miss fire the blue peter is the signal. The 'preparative flag' is also lowered. The yachts in the race are under the rules at first gun (Rule 17). The only apparent exception being that a _paid_ hand may join or leave a yacht before the 'signal to start' (Rule 14), but not afterwards. N.B.--Corinthians may join or leave a yacht at any time during a race. The race officer should recall any yacht at the start which breaks any racing rule, such as being towed or propelled by any means other than her sails, after first gun (Rule 25). The 'member of a recognised yacht club' (Rule 10) must be on board at _first_ gun, and so with all the other racing rules.