Abstract: The invention relates to a trawling vessel for use with a trawl net (5) for catching marine bio-resources, with a trawl sack (3) attached aft on a trawl net (5) for keeping the catch, said vessel comprising lines (51, 61) for towing and hauling said trawl net (5) and trawl drums (6) for hauling said trawl net (5), characterized by a lock chamber (1) in a stem (21) of said vessel, said lock chamber (1) having a main portion of its volume below said design water line of said vessel, said lock chamber (1) being arranged for hauling said trawl sack (3) with the catch from the sea, through a sluiceway (2) in said stern (21), and said lock chamber (1) being arranged for discharge of said trawl sack (3) and for temporarily keeping said catch; and a trunk channel (16, 12) leading up from said lock chamber (1) and being arranged so that said trawl sack (3), in a generally discharged state, may be hauled up through said trunk channel (16, 12) to a deck (24), thereby leaving said catch in said lock chamber (1).