ABT - About - A conditional term used in qualifying cargo, time, bunkers or speed: when discussing cargo. "about" usually covers a margin of 5 % either way (i.e. 25,000 LT 5% more or less, at owner's option), when referring to a period of time: usually 15 days, although each case is considered on its own merit. In connection with bunkers, "about" has been interpreted to mean 5% latitude; regarding speed, the tolerance is generally one half knot