Charterers might wish to employ their own advisers on navigation and performance and, as a result, various companies have established themselves to advise on weather routeing (like: Fleet Weather USA) and monitor performance. With the exponential growth of computer power these organisations have built up substantial databases of meteorological and technical data. They can therefore be of great assistance to both charterers and owners in some circumstances. However, it is no exaggeration to say that some owners and masters consider that the advice given by routeing companies is an interference with their responsibilities for the navigation and management of the vessel. In ‘The Hill Harmony’  which went to the House of Lords, a routeing company gave advice that a particular course was to be followed in order to achieve the fastest safe passage; instructions based on this advice were given by the charterers but the master ignored them on grounds of safety. The House of Lords decided that the obligation of the master was to prosecute voyages with the utmost despatch and that this included using the route ordered by the charterers unless it could be shown that there was a real danger to the vessel by doing so. As a result of this case it has become clear that routeing may be considered a matter of the employment of the vessel rather than pure navigation as it relates to the commercial exploitation under the charter. However the precise boundaries of what charterers are entitled to order remain to be drawn in relation to detailed routeing. Routeing organisations also provide post-voyage and charter analysis based both on the ship’s information and their own data. It has to be said that there has been a degree of reluctance on the part of arbitrators to prefer routeing material to direct ship’s evidence in performance claims unless the performance clause requires them to do so. In one case, for example, where the routeing organisation data was to be binding on the parties the arbitrators rejected reports produced by the company and said that only the raw material used by it was binding and not the methods employed to produce the reports.