The 42-strong 2018 fleet is split into five classes with racing in the stunning blue waters of the Costa Smeralda off Porto Cervo and around the Maddalena archipelago on the northeast coast of Sardinia.
Porto Cervo is a millionaire's playground and yachties' haven, founded by Prince Karim Aga Khan in the 1960s as a luxury resort for the rich and famous. The Yacht Club Costa Smeralda (YCCS), with its rooftop swimming pool, sits at its heart.
The 140-foot Topaz is one of three elegant J-Class yachts competing at the 29th Maxi Yacht Rolex Cup.
The 100-foot Wallycento Magic Carpet Cubed, owned by British businessman Sir Lindsay Owen-Jones, the ex-head of L'Oreal, came second to Topaz in its class.
The Maxi 72 class holds its world championship during the week, with crews of big-name sailors and affluent owners helming their stripped-out rocketships in perfect conditions.
The historic 130-foot J Class yacht Velsheda was launched in 1933, named after commissioning owner W. L. Stephenson's three daughters -- Velma, Sheila and Daphne. It's now owned by Dutch businessman Ronald de Waal.
The 143-foot J Class Svea, entered by US billionaire Tom Siebel, in action during the Maxi Yacht Rolex Cup.
Three-time Olympic gold medalist and two-time America's Cup winner Jocehn Schumann, the tactician on Magic Carpet Cubed, says: "The Sardinian waters are beautiful to sail on. From the colours to the coastline, they are the most scenic one can imagine. At this time of the year the temperature is also great, we sail in shorts and shirts, and it all happens with 10 and 25 knots of wind. So, beautiful sailing days in the best possible conditions."
The J Class Velsheda, racing in the Supermaxi category, leads the more modern Topaz, helmed by former Olympic silver medalist Peter Holmberg of the US Virgin Islands.
Cannonball, entered by Italian businessman Dario Ferrari, competes in the Maxi 72 class.
American yacht Proteus, owned by Greek magnate George Sakellaris, leads her Maxi 72 rivals through a tight passage in the Maddalena islands.
Downwind flying as the Wally 94 Inti 3 leads rival Vera, which has veteran Volvo Ocean Race skipper Bouwe Bekking in the afterguard.
Maxi 72 Momo, owned by Germany's Dieter Schon, successfully defended its title from Cannonball and Proteus.
American businessman David Leuschen's 100-foot Wallycento Galateia lost her 2017 title to Lyra, owned by Chinese Canadian Terry Hui.
Racing is close and ultra competitive with some of the world's best pro sailors in action.