Currie, of Wanaka, stormed to a breakthrough win last year, claiming the title and the associated world multisport crown in 11hr 6min 51sec.
Tomorrow, in the 32nd running of the 243km multi-discipline race, Currie will continue his rivalry with five-time champion Richard Ussher (Nelson), and will also have some sibling rivalry to consider.
Currie will be joined at the Kumara Beach start line by his older brother, Glen, who finished third in 2011.
''It's the first time we've raced each other in a big event such as this,'' Braden Currie said.
Interestingly, it was Glen who provided the spark for Braden's interest in multisport.
''Glen started racing these. I got the bug, I guess, and haven't looked back.''
Both Braden (27) and Glen (31) are proven stayers. Glen has perhaps been an unsung hero in his brother's past two campaigns, as he has led a well-drilled support crew and been a powerful influence in transition.
Braden Currie said he would not be changing any tactics just to accommodate his brother.
''It will be all on, as far as I'm concerned,'' Braden said.
''There is no way Glen and I will be working together, as a lot of people have said. There is no way I want to sabotage any chances I have. I'll be racing just as hard.
''I'm in good form and plan to have a good race.''
Glen's time in finishing third in 2011 - 11hr 7min 10sec - was similar to Braden's winning time last year, 11hr 6min 51sec, and given favourable conditions, the brothers could both finish in the medals.
The other contender, as usual, is Ussher, whose toughness always commands respect.
Braden Currie was able to give his Nelson rival the slip last year when he attacked on the mountain run, opening up a lead. Ussher will be prepared for that this year.
The Longest Day is about making the most of opportunities, and all three men will need to do just that if they are to challenge Keith Murray's 1994 record mark of 10hr 34min 37sec.
Twenty years ago, Murray benefited from a warm tail wind to make up plenty of time on the kayak leg. His mountain run stage time of 2hr 22min 34sec also remains a record.
Other contenders this year could include Trevor Voyce (Nelson), who finished second in 2009, Sam Manson (Auckland) and Richard Ford (Cromwell).
Coast to Coast
The facts
Course: Starts from Kumara Beach with 3km run to cycle transition point.55km bike to Mingha.34km alpine run up Deception Valley, over Goat Pass to transition at Klondyke.15km cycle to Mt White Bridge.67km kayak down Waimakariri River.70km cycle from Gorge Bridge to finish on Sumner Beach.
Times: Two-day section begins at 7am today (day 1: Kumara to Klondyke; day 2: Klondyke to Sumner).
- Longest Day starts tomorrow at 6am.
- Male winner of Longest Day expected to finish in about 11hr.
- Female winner of Longest Day expected to finish in about 12hr 40min.
- Two-day times are likely to be around 11hr 30min for men and 12hr 50min for women.
