We have reached to conclusion through our recent experiment on the fishing boats builtat the Mitsubishi Nagasaki Shipyard and Engine Works in connection with the rolling motionof ships that in small fishing boats it is desired that the sufficient amount of metacentricheight GM shall be given at about 10 percent of the breadth of ships and that μ₅>3 is foundinsufficient for such small fishing beats while μ₅<2 is considered sufficient, where μ₅ isthe number of swing roquireel to reduce the amplitude, in the instance an amplitude θ=5°to one halb of it.