Abstract: According to the lowest background illumination for some cephalopod species (0.01 lx), using ad-ditive algorithmic procedure of illumination of sea surface, the available illuminating distance between two squid jigging vessels with LED fishing lamps was analyzed. And the formula of the available operation distance from the anchoring position to the near vessel can be described as
. With the formula, when two squid jigging vessels each assemble LED fishing lamps with a total power of 24 kW on one ship side, the available operation distance is 0.78 nautical mile. The formula of the appropriate operation distance between a squid jigging vessel assembling LED fishing lamps and the one with metal halide fishing lamps can be described as
. With the formula, when the power of the LED fishing lamps on one ship side of a squid jigging vessel is 24 kW, and that of the metal halide fishing lamps of another squid jigging vessel is 400 kW, the available operation distance is 1.03 nautical mile.