'The mainlanders like to buy in Europe and Hong Kong ... so we buy to suit their needs,' said Mr Yip, adding that they bought more men's watches than women's.

Watch retailers will also be keeping an eye out for some of the show stealers. 'There will definitely be buyers for the masterpieces. They attract a lot of interest and draw watch enthusiasts into our shops,' Mr Yip said.

One watch that has attracted a lot of attention this year is Patek Philippe's Ref 5350, which uses the brand's latest silicon balance spring, Spiromax. 'Collectors will be going after it. We don't know how many we will be allocated for our sale, so we are not taking orders yet to avoid disappointing customers,' Mr Yip said.

He believes the Rolex sports watches are great value. A Daytona watch worth upwards of $30,000 has a much more active second- hand market than sports watches of other brands in a similar price range.

Breguet's double tourbillon (Classique 5347) at $2.7 million-$2.8 million, is an eye-catching timepiece, with the tourbillons going around the dial along with the hour hand. Also impressive is the Tradition 7037, with transparent front and back to expose the intricate mechanism.

Eldorado Watch's director, Raymond Chan Pak-man, has put a few Patek Philippe's Ref 5960s into his shopping basket. He likes its unique combination of a fly back chronograph with annual calendar. At the retail price of $413,000, he believes watch lovers will find it good value.

He also finds the Patek Philippe Ref 5119 a good entry-level watch. The model, which replaces the ultra-thin Calatrava Ref 3919, sports a clean, modern and elegant look with a larger (36mm vs 33.5 mm) diameter case and its small seconds hand in a subsidiary dial at the 6 o'clock position. The yellow gold version will retail for $92,500 when it arrives after June.

Another best-seller will be the Annual Calendar Ref 5396 ($226,500) with a simple graphic design featuring two windows for day of the week and month at 12 o'clock, and a date window at 6 o'clock.

For women, Mr Chan believes Patek Philippe's Calatrava Ref 4896 ($130,000) will dazzle. 'There used not to be so many [mechanical watch] choices for women as Patek tends to focus on men's watches. But this year Ref 4896 with its night-blue dial etched in concentric circles is superbly done. I think it's very attractive. The larger size will be popular too,' he said.

Ref 4896 is Patek's first ultra-thin mechanical watch for women and is powered by the thin and compact Calibre 16-250 movement, which is 2.5mm thick and 16.3mm in diameter.

He believes Rolex's boy-sized Oyster with a 31mm diameter, priced from $20,000 to more than $100,000, will also be popular for its vintage look, refined mechanical functions and comfort.

Omega continues to be a hot favourite in the mainland market due to the brand's active promotions there. Mr Chan believes that this year's collection, most of them fitted with co-axial movement, will find renewed enthusiasm among consumers. The 007 Seamaster ($21,900-$23,300) will be popular because of its limited edition, its co-axial movement and its classic style, he said. The Aquaterra ($29,900), with unique functions for calculating the start time in yacht races, will also be much sought after.