Upon the completion of each voyage, a Post Voyage Analysis report is issued to owner/operator or charterer. This post voyage analysis report contains a detailed breakdown of the days which were ‘good weather days’ and those which were not. The speed and consumption of the vessel is calculated within the ‘good weather days’ to show any time gained or lost, and whether there was any overconsumption of bunkers during that period as to the speed and consumption that was agreed between the parties in their Charter Party. Should any underperformance be found during the good weather period, it will then apply to the whole voyage basis the legal stance that if vessel underperformed in good weather, then it follows that it would underperform in bad weather as well.
‘Good weather’ days are defined in the chapter party and therefore it is very important to negotiate clear and concise terms for what will constitute this period of good weather. Whilst Beaufort Force 4 and Douglas Sea State 3 are the usual parameters given, it is recommended to be more specific for the Douglas Sea State and add the specific significant wave height it will amount to (e.g. 1.25mtr, 1.5mtr, 2mtr). This is due to the fact that there is no legal definition acknowledged globally, which may lead to disputes of what constitutes good and bad weather periods.