The Division of Ports and Harbors (DPH), part of the Pease Development Authority, is the port authority for the Port of Portsmouth. The DPH plans development and maintenance of the ports of New Hampshire to foster commerce and help shipping and commercial maritime interests transport their products. The DPH also facilitates accommodations for area boat owners, pleasure fishermen, and others traveling the New Hampshire coastline and rivers.
The Port of Portsmouth is an ice-free deep-draft port operating throughout the year. The Port of Portsmouth's DPH Market Street Marine Terminal is the only public access general cargo terminal on the Piscatagua River.
The Port of Portsmouth's Market Street Terminal has one 182.9 meter long berth with alongside depth of 10.7 meters and one 95.1 meter long berth with alongside depth of 6.7 meters. At three nautical miles from the open sea, the terminal is located less than one kilometer from the busy Interstate 95 highway and just over three kilometers from the Pease International Tradeport, a 1.2 thousand hectare business and aviation park. The Market Street Terminal has over 4.6 thousand square meters of covered warehouse, 3.2 hectares of paved outside lay-down area, and on-site rail access.
The Port of Portsmouth handles bulk cargoes (salt, wood chips, scrap, etc.), breakbulk (construction materials and machinery and industrial parts), project cargo (vacuum tanks and power plant components), and containerized cargoes.
Foreign Trade Zone #81 includes five sites and one subzone, including 4.5 hectares at the Port of Portsmouth's Market Street Terminal, 30.4 hectares at the Portsmouth Industrial Park, 20.2 hectares at the Dover Industrial Park, 566 hectares at the Manchester Airport, and 769 hectares at the Pease International Tradeport.
The DPH also manages a wide range of passenger vessel facilities that serve charter boats for fishing, diving, cruising, and sightseeing as well as party fishing boats, whale watching boats, ferries, and cruise ships. The Port of Portsmouth also contains berths and slips for commercial fishing vessels.