William Biccio of Boston, a veteran of the 1976 and 1992 tall ships visits, agreed that the ships should have come in closer together. However, he praised the international flavor of the festivities.

"People got to see a bit about every country--a happy little world," Biccio said. "It's more like a world celebration. America opened the doors to all the nations."

Many of the true enthusiasts staked out prime spots on Castle Island early in the day.

"I've been at Castle Island," Spiros said. "It's crowded, but good viewing."

One of the most popular attractions during the week did not even participate in the parade. The aircraft carrier USS John F. Kennedy arrived on Monday morning and was open to the public later in the week. The carrier was escorted by a pair of cruisers, the USS Hue City and the USS Vicksburg and by a destroyer, the USS McFaul.

The Constitution, the oldest commissioned warship in the U.S. Navy, was towed out to sea to begin the parade by escorting the other Tall Ships into the harbor. As she re-entered the harbor at the head of the procession, an artillery salute in her honor was fired from the shore. The artillery also fired salutes to several of the other Tall Ships as they entered the harbor.

Throughout the week, the ships will be docked and open for public boarding. Most of them will depart on Sunday, exchanging a salute with the Constitution before they begin racing to Halifax, Nova Scotia, and then on to Amsterdam.

--Yibei Shen contributed to the reporting of this story.