Boat watching a favorite pasttime in Port Aransas

Dolphins can frequently be seen cavorting ahead of ships in the Aransas Channel. People who walk out on the north and south jetties to fish or sightsee have a perfect vantage point to observe what is sailing into or out of the Aransas Pass that links the Intracoastal Waterway to the Gulf of Mexico.

They can watch the fishing boats, sailboats and ships that navigate the Corpus Christi Ship Channel, the Aransas Channel or the Lydia Ann Channel.

Boat watching is a popular pastime, not only on the jetties, but at Roberts Point Park from a vantage point in one of the restaurants in the flats or even from the bulkhead or the pier in the Charlie's Pasture Nature Preserve off Port Street.

It's interesting, and it's free.

Visitors and full-time residents will see huge oil tankers, cargo ships, barges, fishing boats, shrimp boats, sailboats and yachts, to name a few.

Ninety percent of the ships that move between the jetties are either petroleum or chemical tankers coming from or going to the nation's 10th-largest port in Corpus Christi via the city's ship channel.

An oil tanker enters the Aransas Channel at Sunrise. Ten percent of the ocean-going vessels are likely to be carrying grain or other bulk cargo, and even raw materials for the Reynolds Metals aluminum plant at Ingleside.

Tankers will typically possess long, uncluttered decks, with one or two cranes to help move items for loading or unloading.

"No smoking" signs are usually painted prominently on the superstructure of tankers, grain carriers and other vessels.

The identity of a vessel is fixed on the bow of the ship, and on the stern. The ship's name will be prominently displayed in both places, with the ship's home port displayed usually on the stern.

The ship's name could be painted in English on the bow and in the language of the home port on the stern of the vessel.

Ships display the flag of their host nation from the starboard spreader (right side, on the wire or rope that connects the mast to the deck) as long as they are in that nation's territorial waters, but there is no law requiring this custom.

The ship's home flag will be flown from the stern (rear) of the ship, on a mast. (for a list of nations' flags, visit www.crwflags. com/fotw/flags).

Special signal flags are flown from the port (left side) spreader, and these flags each represent a letter of the alphabet or a numeral and has its own special signal meaning.

The most commonly seen flag is a red (B, or Bravo) flag that indicates the vessel is carrying dangerous cargo such as petroleum.

Flying this flag on the ship is required by law. Another commonly spotted signal flag is the blue and white international "A" or "Alpha" flag that indicates that a diver is in the water near the vessel.

Other sights on a ship include the symbol indicating a bulbous bow, which is a hemispherical projection beyond the usual bow of the ship. It is normally under water unless the ship is empty.

This recent design in ships provides an increase in fuel efficiency and speed, and is used on almost all new ship designs. The bulbous bow symbol is an outline of the underwater part of the bow, and it is usually located at or near the ship's name on the bow.

The Plimsoll line is often not seen on ships, but was once an integral part of the symbols associated with a vessel. It consists of a painted circle divided horizontally by a line and a vertical line with several horizontal projections, each with one or more letters.

The Plimsoll line circle indicates the ship's normal water line; if there is an L R associated with the circle, it indicates that the ship is registered with Lloyd's Registry, the famed British shipping insurance company.

The vertical line with perpendicular markings shows the safe load levels for different weather and water conditions. They are (from the top) TF (tropical fresh water), F (fresh water), T (tropical salt water), S (summer), W (winter) and WNA (winter North Atlantic, where oceans are particularly stormy).

The shipping company that owns the ship will invariably display its symbol on the ship's stack. This can be a geometric symbol, a letter of the alphabet, the company's logo, or virtually anything else.