It is important that, when buying bunkers, attention is paid to the specification of the product. In order to double check that the bunkers actually supplied are the same quality as the bunkers bought, many shipowners are now using the services of an independent quality analysis service. It is vital that the ship manager also persuades the officers in the ship’s engine rooms to be equally quality conscious because they are the ones on the spot where the supply is made. This is particularly important when a ship is on a time charter as, under such a charter, the supply of bunkers becomes the charterer’s responsibility and so the ship manager loses direct control over quality. Charterers will always be anxious to keep costs to the minimum and one has to face the fact that they are not directly concerned with the long-term condition of the machinery. ‘The shortest distance between two points is a straight line’. This rule does not work at sea. The first and most obvious example of this is governed by the fact that the world is a sphere and that therefore the ship has to travel round the surface of the sphere, which on an ordinary chart using the Mercator Projection would show as a curve. To this has to be added the effect of tides, currents, prevailing winds and the occasional storm. Both tides and currents can have significant effects on a vessel’s performance. A prudent Master will plan his voyage so that he can take the full benefit, where possible, of these two factors, even to the extent of deviating from what would appear to be the normal course. It is as easy to imagine the result of having the welcome assistance of an ocean current moving at a speed of, say, 4 knots, as it is to imagine the effect of having to spend several days punching into a contrary current moving at a similar speed. A storm can equally well affect a vessel’s performance not only forcing it to slow down, even to the point of zero progress, but also increasing the risk of damage to the ship and to the cargo. A prudent Master will, if possible, alter course well in advance to avoid sailing too close to a storm.