The project to create the fishing ground in the open ocean by rising Deep Ocean Water (DOW) has been carried out since April 2000, sponsored by Japanese Government Fisheries Agency and Marino-Forum 21. DOW is discharged into the euphotic layer as a density current where photosynthesis can be done by DOW's rich nutrient salt. The name of this machine is called Ocean Nutrient Enhancer (ONE for short). The outline concept of the ONE is ; “Rising DOW of 500 m depth and 500, 000 m³/day with the special impeller, which also sucks the surface water in order to make a mixed water of proper density.” “Discharging the nutrient rich mixed water continuously and making density current at the euphotic region.” “Increasing the phytoplankton (primary production) on the layer of the density current.” “Increasing fishes in the above sea area.” “Power for driving the impeller is supplied by OTEC (Ocean Thermal Energy Conversion) using a cold characteristic of DOW.” To confirm the characteristics of the density current in Sagami Bay where the real sea experiment is scheduled, the scale model experiment of 1/200 in the continuously stratified salty water tank was carried out. And the suitable discharge velocity to maintain the rich nutrient in the density current layer was researched in the way of 2 and 3 Dimensional flow experiments. In conclusion, the thickness of the layer of density current in Sagami Bay in Summer season was estimated about 12 m, and the thinning ratio of DOW in case of using 3 Dimensional ring nozzle is from 3 to 4 times, according to the analysis of a low of similarity. These results are very valuable for designing the ONE that is scheduled to be set-up in Sagami Bay in the year 2003.