ABSTRACT

The variable X has an exponential distribution (Ciletti 1978, Fujii 1977, Gucma 2003, Kasyk 2004, Nelson 1995). In this paper the variableY has a normal distribution (Kasyk 2006). When the ship is forced to sail after the more slowly unit, she must reduce her own speed. The longest time necessary to cover the fairway section on which the order to maintain minimum distance exist is equal to d/vav, where d is the length of this section and vav is the average velocity in this section. While the shortest time of covering this fairway section amounts d/vmax, where vmax is the highest velocity in this section. On narrow fairways, usually the average velocity doesn’t differ much from the maximum velocity. Hence the variable W can be described by an uniform distribution on the interval from d/vmax to d/vav.