The stately square-riggers known as the Tall Ships hark back to the Great Age of Sail, and particularly to the early 19th century when hundreds of these vessels roamed the oceans. Today there are only about 30 Tall Ships left in the world, and two-thirds of them will join this year's big parade, Operation Sail, to cruise past the Statue of Liberty on the Fourth of July. Some will also visit other East Coast ports, and many will gather on the West Coast July 26 to 31 at Expo 86, Vancouver's world's fair. Closest to home, major welcoming festivities for the ships and their crews are planned at Baltimore and Norfolk.

*Baltimore: Baltimore will see the Tall Ships on their way to -- and on their way back from -- Liberty Weekend '86 in New York.

What Baltimore calls its Summer of Sail, originally a celebration of the Tall Ships, has taken on a somber commemorative tone with the loss at sea last month of the Pride of Baltimore, the city's clipper schooner. On June 14, the city will honor the Pride with a parade of sail. The tall ship Elissa, from Galveston, making a special visit for the occasion, and a fleet of 25 smaller sailing ships will enter the Inner Harbor with flags at half mast.

Other Tall Ships will arrive for Summer of Sail at scattered times, with the schedule currently as follows: Cuauhtemoc of Mexico, June 19-23; Capitan Miranda of Uruguay, June 23-28; Danmark of Denmark, June 25-29; Dewaruci of Indonesia, June 27-28; Shabab Oman of Oman, July 10-12; Guayas of Ecuador, July 10-13; Kyrenia of Greece, July 11-13; Amerigo Vespucci of Italy, July 12-17; and Simon Bolivar of Venezuela, July 12-15. All will be open for public tours at least part of their stay.

On June 27, when the Danmark, the Capitan Miranda and the Dewaruci are in port, a public crab feast is planned at Rash Field at the Inner Harbor, beginning at 6 p.m. Five ships will be in port the weekend of July 12-13.

*Norfolk: Norfolk has scheduled its own parade of sail at noon on Monday, June 30, for five of the largest Tall Ships -- and lots of accompanying vessels, including military ships and private pleasure craft. The ships depart Town Point Park at the conclusion of a long weekend of celebratory events and will cruise up the coast "in-company" to the Statue of Liberty centennial.

Three of the big ships that will visit Norfolk are from South America -- the Libertad of Argentina, the Esmeralda of Chile and the Gloria of Colombia -- so the festival has been dubbed "Liberty Sail of the Americas -- Norfolk to New York 1986," and it has a definite Latin American flavor.

A two-day party of Latin music, food, dance and arts and crafts will be held June 28 and 29, at Town Point Park, adjacent to Norfolk's new Waterside market. During the weekend, the five Tall Ships -- also including the Elissa of Galveston and the Bluenose II of Nova Scotia -- will be open to public tours (at hours to be set by their commanding officers).

A week earlier, on Saturday, June 21, a mini-parade of sail will welcome the Eagle, the U.S. Coast Guard Sail Training Ship, which will be docked at the harbor until June 24. Other visiting Tall Ships at that time will be the Capitan Miranda of Uruguay (June 17-23) and the Guayas of Ecuador (June 20-28).