Floodable length

Floodable length is the greatest length of a compartment, centered at a point, that can be flooded without immersing the ship past the margin line (76 mm below the bulkhead deck at side). Plotted as a curve along the length and divided by a permeability and a factor of subdivision, it sets the maximum permitted spacing of transverse watertight bulkheads under the deterministic subdivision rules that preceded the probabilistic SOLAS Ch. II-1 method.