The Bottom Sampler acc. to Van Veen is a qualitative sampler to achieve low-disturbed sediment samples in soft or medium hard grounds from any desired depth. It consists of two clamshell jaws connected by a hinge. During descent both levers are locked wide apart and the jaws are open. Upon touching the water bed the locking mechanism is released and when the rope is pulled taut to raise the sampler the jaws close. During retrieval the jaws are holding the sample and prevent sample wash-out. Additional flaps on top of the heavy version 437 333 allow to inspect the sample before retrieving.