My experience is to present precedence to Arc7 +- 25nm up till about 20S. I take the Inmarsat knowledge as a gift/contribution to science And that i need to follow it, Unless of course needless to say we uncover some new facts/secrets and techniques. David Griffin, a CSIRO drift-modelling scientist http://hbr-case-study-solution51358.ampedpages.com/5-Essential-Elements-For-Ocean-carriers-19250584