When a bows-on approaching vessel yaws (or swerves) so badly that she only appears end-on to you now and again, she must be treated as a bows-on vessel all the time.
Xa ugobo lwenqanawa lujika ngokungekho mbekweni kubonakala umva wayo kuwe, mayiphathwe njengenqanawa egobileyo ngalo lonke ixesha.