When Nova Scotia's Picton Castle sets sail from Lunenburg Harbour on a round-the-world voyage this spring, it'll have a little something special sloshing about in its hold.

On Wednesday, four big barrels holding 900 litres of rum were hoisted on board. It's nothing unusual in a town that once saw fishermen abandon cod to smuggle booze into the U.S., but there is a twist.

The Picton Castle will indeed head straight for the U.S., stopping in New Orleans, but it will keep the rum on board, sailing it to the Galapagos Islands, Pitcairn Islands, across to the Cook Islands, Indonesia, South Africa and Bermuda, before landing right back in Lunenburg.

Crews hoist a barrel of rum aboard the Picton Castle this week. (CBC)

The rum's owner, Pierre Guevremont of Ironworks Distillery, says this rum is meant for Nova Scotians.

"The interaction of the barrel and the movement of the barrel, and the interaction of the spirit in the oak, is always something that improves the taste of the rum," he said as the barrels went on board.

"And that's where aging comes from: from sea captains who said, 'This rum tastes better at the end of the voyage than the beginning.' And so what was a method of transportation became a methodology of improving the quality of the spirits."

It doesn't hurt as a promotional tool, he admitted.

About 225 litres of Ironworks Distillery rum is carefully lowered into the hold. (CBC)

Slipping barrels of rum onto a ship in Lunenburg has a long and shady history. Far from seeking publicity, the Nova Scotians who replaced fish with booze in the 1920s and 1930s tried desperately to avoid attention.

Nova Scotia went legally dry during the First World War and remained so until 1930, much like the U.S. But Canadian distilleries could legally make and export alcohol and transport it by sea — just not into America.

In the 1920's and 30's - many sailors in Nova Scotia did the unthinkable - they stopped fishing and became international smugglers. 16:03

And yet at one point, 90 per cent of the schooners in Lunenburg Harbour were smuggling spirits into the U.S., handing it to criminals under the cover of darkness along the Boston and New Jersey coast. One Nova Scotian captain who brought his illegal cargo right into New York Harbour died when authorities fired on the boat.

The crew of the Picton Castle, a 55-metre, steel-hulled, square-rigged barque tall ship, expect to face significantly less trouble.

The biggest risk is likely a thirsty crew of 40 men and women eyeing the casks somewhere in the South Pacific.