The research and monitoring programmes at Marine Scotland Science have demanding requirements for sampling at sea. Basic zooplankton sampling devices consist of towed fine-mesh nets which collect a single sample of plankton integrated over each deployment. The main requirement of the Marine Scotland Science programmes has been for systems to collect multiple sequential samples during each deployment so as to, for example, resolve details of the vertical distribution of plankton in the water column, with concurrent collection of water samples and measurements of physical parameters. As the research issues have evolved, so these requirements have become even more demanding, with the need to sample to ocean depth of 3 km or more. To meet these requirements, the engineering and electronics team in Marine Scotland Science has developed a number of innovative microprocessor controlled programable samplers, which have been extensively used in a number of projects.