There are, however, customary court approved interpretations of certain words and expressions in speed descriptions/warranties which are of value to list: The word “about” referring to the number of knots is taken to mean a margin of half a knot. “Good weather conditions” are said to be winds of Beaufort Scale 4 or less but it is a well known meteorological fact that it is not only wind strengths which have an effect on the speed or lack of speed of a ship but also currents and sea conditions. Furthermore the effect of a force 6 following wind and a force 6 head wind will be, of course, totally different. Where arbitrators do differ in their methods of assessment is that some prefer the test to be “did the vessel make the charter party warranty of speed on the days when good weather prevailed”, others “was the average speed that the vessel made on the entire voyage taking weather conditions into consideration as well as current, reasonable in relation to the charter party description”. Of these two, the second could be said to be the more equitable method since the former implies a too rigid adherence to the charter party wording itself, whereas the latter has the merit of taking account of all relevant factors – weather, current, sea conditions, etc. Thus the arbitrators will conclude by comparing the time the ship took to complete the voyage(s) in question with the time that the vessel should have taken had she performed at the speed warranted.