Field experiments were carried out with full scale mid water trawl nets and ships off the coast of Kushiro, between 1979 and 1980.
We present in this paper a new and direct method of measuring the mechanical characters of a mid water trawl. The key point of this method is that all data from each sensor is recorded by analogue data recorder simultaneoulsy and continuously.
By processing these data, we can get various important clues for the control of the motion of mid water trawl and they contribute to its design.