(CNN) -- This month on MainSail
Shamrock V, a 1930's Americas Cup challenger at the J-class race in the Solent, Isle of Wight, in 2001.
What makes a "classic" yacht? Is it age, or era? Are classics born or made? Is it size and value, or cultural significance?
Classics can be modern and old -- from three-mast 1930s teak works of art like the original America's Cup racers, to cutting edge, contemporary monsters, like the "Maltese Falcon" and the exclusive fleets of luxury boat builders like Perini Navi and Wally.
This month CNN's Mainsail investigates what makes a classic yacht at one of the world's great yachting regattas.
Les Voiles de St Tropez
St Tropez, playground of the rich and famous, a bastion of class, richesse and style, plays host for the 26th year to Les Voiles de St Tropez, a classic event in every possible sense of the word.
The regatta gathers together the most extraordinary modern sailing boats alongside the most beautiful traditional yachts, as sailors from all over the world gather to do battle in the Mediterranean's most glamorous bay.
During the week's racing, presenter Shirley Robertson hitches a ride on board some of the world's most iconic yachts both ancient and modern, and attempts to find out what makes them "classics."
Reporting from Genoa in a world exclusive, Shirley chats to Alinghi team boss, Ernesto Bertarelli and drives the new "Alinghi 5" -- the defender of the America's Cup. Robertson is likely to be the only person in the world outside of the Alinghi team to get her hands on the wheel of the spectacular 90-foot catamaran.
Will this boat, just a few months old, become an instant classic? And in a report from the Perini Navi Cup in Sardinia, boat builders and skippers of the most glamorous luxury yachts on the planet explain what makes their machines the classics of the future.