The boatbuilders of French & Webb put their most recent work-in-progress through an acrobatic right of passage Wednesday, Oct. 5, lifting the the 37-foot hull into the air outside the company’s waterfront shop and flipping it over.

The daysailer/weekender yacht is a new design by Mark Fitzgerald of Fitzgerald Marine Architecture in Camden, commissioned for a family in Cape Cod, according to French & Webb principal Todd French, who said the finished vessel would include some eye-catching work topside.

“It should be a very sculptural exterior highlighting our joiner work,” he said.

As of Wednesday, the boat amounted to a mahogany hull, recently clad in gray fiberglass. Bottom up, it resembled a submarine, and French joked that the company had landed a naval contract.

Starting construction of a new boat upside down is typical, he said, because it’s easier to work on the hull from above — imagine, for example, sanding the underside of a boat in its regular orientation. The deck, too, is easier constructed from above, so when the major work of the hull is completed, the whole thing is flipped over for the next phase of construction.

So how do you flip a 37-foot hull?

French & Webb used a massive truck-mounted crane suspending a cradle made from two, thick, nylon straps looped under the hull. The crane operator lifted the boat off the ground, then elevated one side of the cradle causing the hull to roll over in the straps.

Wednesday afternoon was especially windy, but the flip went off without incident.

A forklift operator positioned the boat’s 4,400-pound fin keel below the suspended hull, and French directed the crane operator as he and business partner Peter Webb aligned a wicket of bolts with matching holes in the hull. The larger piece was then lowered carefully into place and bolstered with boat stands to keep the top-heavy assembly from tipping.

The French & Webb 37, as the boat is called, was started this summer and, according to French, is due to launch in early spring 2012.