摘要:For reduction of Greenhouse Gas (GHG) emission from shipping sector, low GHG emission ships are required to be built and promoted. On a project for 10mode at sea, a calculation method on decrease of ship speed has been developed. The calculation method has confirmed by tank tests.Full-scale onboard measurements have been conducted for four kinds of ocean-going ships in operation; pure car carrier, very large crude oil carrier, container ship and bulk carrier, with a view to attesting the reliability of the method for evaluating ship performance in actual seas. In this paper, results of onboard measurements for a pure car carrier and a very large crude oil carrier which data accumulate for whole four seasons are reported. The measured and calculated data matched well, showing sufficient reliability of performance estimation for both a fine and a blunt ship type.The results of onboard measurement for the two ships show good agreement with those of the calculation. These results confirmed that the calculation method can be accurately applied to both a fine and a blunt ship type.