Ocean drive; In Florida, the sunniest get-together is an offshore picnic for family and friends William Norwich climbs aboard.

Byline: William Norwich

People never say no to a Magnum," says Alison Spear with a laugh. She's referring, of course, to the Lamborghini of pleasure craft, capable of seafaring speeds upwards of 70 mph.

The Marchesa Katrin Theodoli, Magnum's president and CEO, has lent Spear a perfect pearl-gray one for a picnic this afternoon in Miami. The U.S. Navy and Coast Guard have Magnums for their highest-priority patrolling. Christina Onassis left her ruby-red Magnum to her daughter, Athina. The king of Spain has one, as do Italy's Berlusconi, the emir of Kuwait, and rock 'n' roll's Lenny Kravitz. (Lenny's was originally outfitted from stern to bow in Roberto Cavalli everything-though we're told it was recently redone to be more "shagalicious.")

Spear, a noted architect and mother of two, is passionate about entertaining whenever, and wherever, she can-despite her hectic work schedule, which currently includes a new pied-a-terre for Bottega Veneta designer Tomas Maier and a new interior for Nicole Miller's South Beach boutique.

Stocking up for the boat picnic at the Sunday-only farmers' market on Lincoln Road-making a beeline for the remarkable desserts at Antella Jones's stall (Jones is a local paralegal who bakes on weekends and commands a ...