A low-volume submersible drift-pump unit is described for the collection of demersally drifting biota, particularly for shallow aquatic situations. This unit collects less motile biota quantitatively (so far zooplankton, larvae of macrofauna, and meiofauna are successfully collected). It can easily be modified for the sampling of a variety of other aquatic organisms, in particular nano- and picoplankton (algal, bacterial, fungal and viral plankton) at high temporal and spatial resolution. A new drift-net unit allows qualitative comparisons of demersally drifting invertebrates. Both light-weighted stationary systems can be modified for sampling at varying distances from the bottom and are suggested for fine-scale appliances at moderate depths from shore, pier, boat, or deployed by divers.