A serious of study is carried out to practical use of the three-slot cambered otter board improved by the authors. As the first step, we designed main plates, slots and accessories, such as holding plate, fan-shaped towing plate, normans, center ring, etc. Standing on this design, we made the simple cambered and three-slot cambered model otter board with accessories in a linear scale 6:1. and carried out model test to examine the efficiency of these boards. The obtained results can be summarized as follows: 1. On the simple cambered board with accessories, the values of the maximum shear coefficient(C LX ). drag coefficient((C D) and hydrodynamic efficiency(C L/C D ) are 1.39, 0.56, 2.48 at 22˚ of the angle of stall respectively. 2. On the three-slot cambered board with accessories, C LX/C D and C I/C D are 1.67, 0.92, 1.82 at 32˚ of the angle of stall respectively. 3.C LX of board with accessories is smaller 10~12% than that of only the main plate, and the angle of stall is almost same. 4. C LX and the angle of stall of the three-slot cambered board with accessories are greater 20% and 〈TEX〉10˚〈TEX〉 than that of the simple cambered board respectively.