As of the census of 2000, there were 3,370 people, 1,542 households, and 993 families residing in the city. The population density was 382.5 people per square mile (147.7/km²). There were 3,794 housing units at an average density of 430.6/sq mi (166.3/km²). The racial makeup of the city was 93.92% White, 0.42% African American, 1.25% Native American, 0.86% Asian, 0.03% Pacific Islander, 2.17% from other races, and 1.36% from two or more races. Hispanic or Latino of any race were 6.08% of the population.
There were 1,542 households out of which 22.6% had children under the age of 18 living with them, 53.6% were married couples living together, 7.3% had a female householder with no husband present, and 35.6% were non-families. 29.1% of all households were made up of individuals and 8.7% had someone living alone who was 65 years of age or older. The average household size was 2.18 and the average family size was 2.64.
In the city the population was spread out with 18.9% under the age of 18, 5.7% from 18 to 24, 25.2% from 25 to 44, 34.6% from 45 to 64, and 15.7% who were 65 years of age or older. The median age was 45 years. For every 100 females there were 108.4 males. For every 100 females age 18 and over, there were 106.6 males.
The median income for a household in the city was $39,432, and the median income for a family was $46,719. Males had a median income of $28,000 versus $22,393 for females. The per capita income for the city was $23,681. About 7.1% of families and 11.3% of the population were below the poverty line, including 17.4% of those under age 18 and 3.5% of those age 65 or over.
A United States Census taken in 1925 showed a firmly committed 250 people living on the Island, and show a firm population of 300 by 1931. A toll road was opened in 1931 between the town of Aransas Pass and the Ferry Landing of Port Aransas. Before the toll road, you had to buy a ticket, load your car onto a flatbed or train and use the wooden planks inside the rails when the train wasn't on a scheduled run. With the toll road, drivers could now just pay a toll and drive on a wooded plank structure built next to the rail tracks. Once the railroad closed in 1947, it was used only to traffic automobiles until 1960, when the state built a new and modern road to Harbor Island from Corpus Christi and the ferry landing.
Today, the Port Aransas Ferry System provides free transportation service seven days a week, twenty-four hours a day. The ferry ride connects Mustang Island and Port Aransas with the mainland via Aransas Pass. There are six large identical ferries that can carry twenty regular passenger vehicles on each trip. Each boat can move 100 vehicles per hour.
In 1935 Dr. E.J. Lund, a zoologist from The University of Texas, traveled to Port Aransas to investigate a massive fish kill. He constructed a small rough lumber one-room shack on the old Corps of Engineers dock. Dr. Lund recognized the uniqueness of the local environment and the need for public education about the natural resources of the Gulf of Mexico and gradually rekindled interest in marine science at the University.
In 1941 The University of Texas Marine Science Institute was officially formed with Dr. Lund as the first Director. Research began in the old pier building with one of the first projects being on the distribution, life history and relative abundance of marine fishes of Texas, by Dr. Lund and Dr. Gordon Gunter, who was Lund’s student and later followed Lund as Director. Gunter also undertook a study for the U.S. Navy on the problem of fouling on ships’ bottoms.
With the end of the war, development of the Institute resumed. Lund purchased and donated 12 acres (49,000 m). The old Army Corps of Engineers building, constructed in 1890 and veteran of several hurricanes, was included. This building is still there today and serves as a dormitory where students still relax on an old fashioned porch and watch ships and porpoises almost at the doorstep on the Aransas Pass.
In 1946 the first permanent marine laboratory was established in Port Aransas, Texas. Two frame buildings were constructed, which still serve as the cafeteria and a dormitory, and a full time staff was in residence. A laboratory was built on the pier in 1948 and major expansion of physical facilities took place in the 1970s with the acquisition of 49 acres (200,000 m) of land, additional laboratories, dormitory, apartments, maintenance complex and a 5¼ acre boat basin.
During World War II, an artillery gun turret was erected by the United States Army and maintained throughout the war, on a high dune just off Cotter St. across from the UT campus, and is now part of the UT properties. It was placed to protect the pass from reported sightings of German U-boats. Blackouts were called on all the Island during nighttime hours, no fires on the beach or car lights, and house windows could not show light either and had to be covered with heavy curtains, blankets or wood.
In the early 1900s, tarpon fishing began to attract anglers and tourists from across America to Port Aransas. However, because of the choppy waters around Port Aransas, access to the Gulf Coast was restricted. The boats of the day were not designed or built to handle the rough Gulf Coast waters and storms in the early 1900s wiped out the existing charter fleet.
To meet the needs of anglers coming from across the country to fish for tarpon, the Farley Family began building the Farley boat. In 1915, Charles Frederick Farley and his son established Farley and Son, Boat Builders in Port Aransas.
The Farley boats were designed and built to meet the needs of anglers and fishing guides. They were designed with low-sides and a high bow to fight the choppy waves and were well equipped for the Gulf Coast chop. The Farley Boats were also designed with low cabins that allowed fishing in every direction.
In 1937, President Franklin D. Roosevelt visited Port Aransas and while Congress was debating his Judiciary Reorganization Bill of 1937, he fished for tarpon. He hired Barney Farley, the famous fishing guide and brother of Fred Farley.
The president brought his own 35-foot (11 m) fishing boat and Barney Farley agreed to take the President out on the boat. After an unsuccessful outing, Barney Farley convinced the president to fish from a Farley Boat. The President caught so many tarpon that he returned to Port Aransas later that year to again fish with Barney Farley on a Farley Boat.
Today, there are Farley Boat planters located all over the city of Port Aransas celebrating the history and importance of the Farley Boat along the Gulf Coast.
Port Aransas has now become a multi-million dollar fishing, beach and resort village, with summer populations sometimes swelling to 60,000 or more, as well as a college spring-break destination.
Port Aransas was featured on an episode of the FOX television series King of the Hill in 1999, as Hank Hill drove his mother and several of her friends to a miniatures museum in town just as Spring Break arrives. The episode ends with Hank driving his mother's minivan in an effort to reach the last ferry of the day... even though the real-life Port has 24-hour ferry service.