Master Lock Comanche won't focus on elusive double win

Master Lock Comanche will resist the urge to dream of a rare line honours and handicap double win as the Sydney to Hobart fleet prepares for an action-packed race from Boxing Day.

In 78 previous editions of the 628NM race, only seven times has the boat that crossed the line first also been awarded the overall victory once handicap has been factored in.

Today, only an 100ft supermaxi can realistically claim line honours, and those boats typically score poorly on handicap due to their larger masts and size, water ballast and other high-tech features.

Legendary supermaxi Wild Oats XI, the most successful yacht in Hobart history, was the last to achieve the double, doing so when she broke the race record in both 2005 and 2012.

Before that, the feat had not been achieved since 1987, when the largest boats did not yet measure 100ft.

But this year's weather forecast has created expectations of a "big boat race" in sailing parlance, one in which conditions will allow for the 100ft supermaxis to make fast passage to Hobart and dominate their smaller competitors.

The fleet of 104 boats is expected to begin the race from 1pm in a north-easterly that will propel the four supermaxis down the NSW coast at speed.

Provided they can avoid storm damage, a west-south-westerly change in the Bass Strait should allow those four big boats - Comanche, LawConnect, Wild Thing 100 and Maritimo 100 - to maintain their pace on the first night of racing.

There's a chance the winning supermaxi will go fast enough to balance out her unfavourable handicap, says James Mayo, one of two new co-skippers on line honours favourite Comanche.

"Anything's possible when you go racing," he told AAP.

"Definitely the forecasts presents some possibilities. But we don't think about that (double win) at all.

"It'll be what it's going to be. If you focus on the process, the outcome will generally look after itself."

Keeping the asset and her crew safe on the water will be a higher priority particularly across the first 24 hours of racing, when the forecast is wilder.

As the boats enter the River Derwent, the race will become highly strategic as Comanche looks to avoid a repeat of last year's 51-second loss to LawConnect, which took line honours.

"It's going to be pretty much keep the boat together for the first bit of the race and then it's going to get quite tactical in terms of how you close the Tasmanian Coast," Comanche co-skipper Matt Allen told AAP.

"If you get too close you might run out of breeze, but if you get too far out, you might be against the shift of the breeze.

"It's really going to be a tactical, complicated race towards the back end, but it's keep the boat together for the first bit.

"It's going to be a challenging race."