An amended NYPE c/p specified in its description clause the parameters on which performance warranties were based including winds not exceeding Beaufort 4 and waves not greater then DSS3, no adverse current, no swell. The Tribunal rejected Charterers’ argument that these parameters were negated by a separate weather routing clause, and found that the performance analysis of Charterers’ weather bureaus was inconsistent with the description parameters by (i) the use of ‘significant wave height’ (ii) applying a positive current factor but not recognising an adverse one or swell.