A new basin for seakeeping and maneuvering studies has been under construction at the Chiba Campus of the University of Tokyo and was completed in March 1970. The principal dimension of this basin in 50 m × 30 m attached with 30 m × 3.5 m approach way with 2.5 m of water depth. Most unique feature of this basin is that it is installed by a set of X-Y carriage, i. e., a main carriage which has 30 m span moves longitudinal way of the tank, and a subcarriage which is hanging down from the main carriage moves transverse way. Therefore like an X-Y recorder, the subcarriage can chase the model ship whatever the motion of it. The basin is also fitted by a hydraulic wave maker of 50 m length.