The momentum of the ship depends upon the mass of the ship and the speed of the ship. Thus a lighter ship will gain or lose speed faster than a deeply loaded ship. If a large tanker is taken as an example then at the same speed it will travel longer after the engine is stopped – when the tanker is in full load condition. The reverse will happen when the tanker is on ballast – that is it will travel a lesser distance. For starting up also after the first movement is given a loaded tanker will come to the designed speed slower than the same tanker when it ballast.