A white squall is a sudden and violent windstorm phenomenon at sea which is not accompanied by the black clouds generally characteristic of a squall. The name refers to the white-capped waves and broken water, its meager warning to any unlucky seaman caught in its path. White squalls are rare at sea, but common on the Great Lakes of North America.

A white squall is the culprit of many sea stories and blamed for quite a few tragedies. It is described as a sudden increase in wind velocity in tropical and sub-tropical waters, and lacks the usual dark, ominous squall clouds. The white squall, still thought by some to be myth, may be a microburst.[1]

The Pride of Baltimor:
"On May 14, 1986, returning from Britain on the trade route to the Caribbean, the Pride was struck with what the US Coast Guard later described as a microburst squall (see also: White squall) 250 nautical miles (463 km) north of Puerto Rico. The vessel was hit with 80-nautical-mile (148 km) hour winds, capsizing and sinking her. Her Captain and 3 crew were lost, and the remaining 8 crewmembers floated in a partially-inflated life-raft for four days and seven hours with little food or water until they were rescued by the Norwegian tanker Toro.

The Pride's lost captain and crewmembers (Armin Elsaesser 42, Captain; Vincent Lazarro, 27, Engineer; Barry Duckworth, 29, Carpenter; and Nina Schack, 23, Seaman) are remembered to this day with a memorial on Rash Field in Baltimore's Inner Harbor."

The Marques:
In the summer of 1984 she sailed to San Juan, Puerto Rico to compete in the Cutty Sark Tall Ships' Races.
The Bark Marques won the first tall ships' race, from Puerto Rico to Bermuda. The ship left Hamilton on the second race, bound for Halifax, Nova Scotia, on 2 June 1984. On the night of 2 June the ship ran into a gale. In the early hours of 3 June she was hit by a sudden squall and a large wave, possible a rogue wave, and was knocked down onto her side. Although the ship had been converted to a sail training and charter cruise ship, she had retained the main cargo hatch from her days as a commercial vessel. When she was knocked down the main hatch was breached and water flooded into the interior of the ship. She sank in less than a minute, with the loss of 19 of her 28 crew members.

The Albatross:
... Mr. Sheldon, now 69, was skipper of the 92-foot brigantine Albatross when the vessel sank suddenly on May 2, 1961, in a fleeting yet violent storm after leaving the Yucatan. Six of the 18 people on board perished.....

The ship went straight down," said Mr. Sheldon, who lives in Norwalk. "I could just see her sinking down out from underneath my feet and beginning to right herself as she went down."

The survivors were able to bail out two heavy wooden lifeboats and were rescued by a freighter two days later.
It all came apart quite suddenly. "It was misting slightly," Mr. Sheldon said. "I was ready for a squall. I was at the main sheet, ready to let out the main. But then it just hit with such force, nothing could be done. We just went right over on our side."

What struck the vessel was what is known as a white squall, what meteorologists call a micro burst. Warm air from the lower atmosphere moves through a pocket above, is cooled suddenly, and descends in a rapid column of cold air....