AWT Weather Routing/Routeing: Applied Weather Technology

Sleeve Miles

by George Schlinkert

Weather forecast models have always required immense computer power to process all of the available data to ensure a timely analysis and accurate forecast. Today’s advanced technology allows real-time winds and waves to be accurately measured around the globe. Similarly, models have been developed that precisely measure and predict ocean currents. GPS and modern navigation systems have transformed the art of navigation into the science of navigation.

While there have been massive improvements in the scientific measurement of real time weather and current conditions, the same cannot be said of the changes made to Charter Party descriptions. Most of the arguments which have been published regarding speed and consumption disputes refer to discrepancies between the log-recorded weather and those recorded by an independent agency, and what the good weather definition actually implies. There seems to have been little or no advance in questioning any of the weather data or position information reported by the Master.

Recent arguments assume the position of the ship is accurately recorded by the Master, and such information should be accepted without question. An arbitration decision that was reported in LMLN 0479 is one of the few cases where the position information recorded by the Master was questioned. The vessel charterers provided clear evidence relating to an undisclosed deviation to Piraeus during a voyage. It was held, “A charterer who discovered that the owner of the ship he had on time charter had deliberately disobeyed orders and had conspired with the Master and crew in an attempt to cover up that disobedience could not thereafter reasonably be expected to have sufficient confidence in any subsequent performance of the charter by the owners and should, therefore, be allowed to say with justification that there had been a renunciation or anticipatory breach.” Clearly this is an extreme example of inaccurately reported information.

‘Sleeve Miles’ is a well-known phrase used in shipping circles to describe the practice of reporting a vessel position slightly behind the actual position. This ensures that should there be a problem with the vessel en route, a stop can be made without the need to inform the vessel charterer, resulting in no reported ‘off hire’. If the slower speed of the vessel is questioned it can easily be put down to the encountering of weather conditions in excess of Charter Party described ‘Good Weather’.

While it is not known how prevalent this practice is, AWT has encountered it in the past and would not expect it to cease any time soon. To address this, AWT offers a position polling service which is the ideal solution to ensure the position of a vessel is correctly recorded as it is automatically reported by GPS. The availability of this data eliminates a source of contention between the parties involved.