Aquilo was a steam yacht which was built in Boston in 1901 for William Phelps Eno, a wealthy man who was the inventor of the stop sign.

In 1910, Eno sold Aquilo and the yacht was brought to the west coast of North America, where it was operated principally in Puget Sound and coastal British Columbia.

[7] In 1910, the yacht was sold to Herbert E. Law, a resident of San Francisco, California, and subsequently taken from Boston around South America to the west coast of the United States.

On January 1, 1910, it was announced that William P. Eno had sold Aquilo to Herbert E. Law, of San Francisco, and James H. Moore, of Seattle.

[5] These were formed into a company called "Western Steel", which held extensive ore deposits in the Puget Sound region.

[5] Having completed recent dry dock maintenance, Aquilo left New York City on December 23, 1909, bound for San Francisco.

[11] In 1920, Aquilo was reported to be owned by H.F. Alexander, president of the Pacific Steamship Company, through whom the vessel was associated with the Tacoma Yacht Club.

[9] In 1944 John W. Eddy sold Aquilo to Edward D. White, owner of the Lakewood Boat Company and Harbor Island Ferries.

[15] On September 5, 1966, while en route from Seattle to Los Angeles, with Campbell and three other persons on board, Aquilo caught fire and sank.

[16] All aboard were rescued by the intervention of a U.S. Coast Guard cutter, Point Ledge, which responded to an SOS signal broadcast from the yacht.

[16] In the weeks prior to the sinking, the Coast Guard had had to assist Aquilo on three occasions, specifically on August 25, 1966, when the vessel was taking on water while in drydock in Seattle on Lake Union, on September 4, 1966, when the vessel reported itself to be disabled at sea 10 miles west of the mouth of the Rogue River at Gold Beach, Oregon, and, on the same day, the Aquilo having been restored to operability, when the Coast Guard was asked to escort the Aquilo into the northern California port of Crescent City, because the crew did not have sufficient knowledge of the waters of that area.