We custom-build all of our linear towed hydrophone arrays. We have built both potted (e.g. polyurethane) and oil-filled arrays for our projects and clients. We have built numerous towed array systems which include the acoustic processing system. We are constantly working to improve our hydrophone arrays, and are currently integrating additional sensors to provide more precise information (e.g. depth, tilt, magnetic bearing) to improve localization accuracy. We can custom-design and fabricate pre-amplifiers to integrate complement our vendor-supplied hydrophones. Most recently we have been experimenting with ultra-high frequency arrays for recording signals from species such as beaked whales and Kogia spp. We are also developing a prototype portable, towed hydrophone system for use on small vessels (e.g. RHIBS) and other small mobile platforms. Over the past 2 years we have been working on developing a 3-D tetrahedral towed hydrophone array for obtaining 3-D localizations of animals, thus alleviating some of the localization ambiguity issues inherent with linear arrays.