THIS year's Corum Cup reaches its finale when a fleet of yachts compete in the last race of the six-race series, an overnight off-shore dash starting off Clearwater Bay. The Champagne Mumm World Cup of Ocean Racing will also be decided today and conditions are forecast to be between light to medium conditions of between 17-23 knots. Picking up from the last race of the series held on Tuesday - the Thai Airways Triangle Race - competitors will line up for the start of the first and only overnight race at 3 pm in the race to Pedro Blanco Rock and back to Clearwater Bay. Race organisers are expecting the first fleet to return home at around lunch-time tomorrow, completing a journey of between 150 and 180 miles. Today's overnight race is the most demanding of the series. The race is worth the most points to yachtsmen whose place at the finish will be multiplied 2.5 times. 'It's going to be a test for sailors in every type of yacht. They would have to get their navigation right and head their races correctly,' said a race spokesman. Battling for overall honours in the IMS class is Corum No Problem, owned by Satoshi Utsumi and skippered by Frenchman Pierra Mas. Corum No Problem, a Mumm 36 one design yacht, won last Tuesday's Thai Airways race in light winds but is going to have a real fight with New Zealand entrant Georgia Express, owned by Jim Farmer. Corum No Problem has made leaps and bounds in the division, finishing second in the Rockport Islands Race, the second race of the series on Monday after picking up on her sixth place finish on the opening day of the series last Sunday in the Steinlager Triangle Race. But Georgia Express has also made strides and is only 3.5 points off the lead with Karl Kwok's Beau Geste, winner of the Rockport Race, a further 3.5 points adrift.