Block coefficient (CB)

The block coefficient $C_B = \nabla / (L \cdot B \cdot T)$ measures fullness as the ratio of displaced volume to the circumscribing box of length, beam, and draft. Dimensionless and bounded by 0 and 1, it runs about 0.50 to 0.60 on fast container ships and 0.80 to 0.85 on VLCCs and bulk carriers. $C_B$ drives wave-making resistance, propulsive coefficient, and cargo capacity, and feeds Holtrop-Mennen powering and the EEDI capacity term. Always state the reference draft, since $C_B$ falls as draft reduces.