Rain or shine, shifts run 18 to 20 hours. Summer temperatures top 100 degrees. The deck is an obstacle course of jagged tackle, whirring winches and tall stacks of 500-pound nets. Ocean spray and fish innards make the floor skating-rink slippery. The ship seesaws, particularly in rough seas and gale winds. Most boys work barefoot; 15-foot swells climb the sides, clipping them below the knees. Much of this occurs in pitch blackness. Purse seiners, like this ship, usually cast their nets at night when the small silver forage fish that they target — mostly jack mackerel and herring — are easier to spot.