4Deep inwater imaging was established in 2008, and is a privately owned, Halifax-based technology firm specializing in the design, production and sale of holographic microscopes. These devices can be used to monitor water in-situ or in lab samples in real-time. These microscopes are based upon the principle of digital in-line holography. Applications include monitoring and quantifying oil in water, harmful algae monitoring, ship bilge and ballast tanks, oceanographic research, food and beverage, aquaculture and algae-biofuel production. The patented software can count, size, characterize and track the movement of particles and microorganisms as small as a 1 micron and as large as several millimeters. Currently, 4Deep inwater imaging's products are used locally, and worldwide in many applications.