The team competed on the circuit in 2011 - an unforgiving introduction to the world of top-level multihull racing. Courses are tight and traffic around the marks can be heavy. Collisions and capsizes are frequent.
"Extreme 40 racing is unlike any other; the teams are very competitive, races are short, the action non-stop and split-second decisions are needed," said Barker.
Racing takes place over four days at each event: one day of open water racing followed by three days of stadium racing. If the breeze is favourable eight to 10 races can be held each day.
Barker's first Extreme 40 event was the last regatta of the 2010 series.
"It was at Almeria, Spain, and we were last."
But they learned what they had to do to become competitive in multihulls, a massive step towards the 34th America's Cup. Barker and crew soon had the measure of the boat and the opposing teams in the 2011 circuit and the crew improved with every regatta, winning the Boston event in May before training in the AC45 became the priority.
Burling and Tuke sailed in three Extreme 40 regattas last year before switching their focus to the AC45 and the Youth America's Cup, wining the regatta in September. This year their Olympic campaign will take priority but they aim to make their mark in the Extreme 40s.
This year the Extreme Sailing Series will race at eight venues: Singapore (February 20-23), Muscat, Oman (March 19-22), Qingdao (May 1-4), St Petersburg, Russia (June 26-29), Cardiff, Wales (August 22-25), Istanbul (September 11-14), The Mediterranean at a port to be announced (October 2-5), Sydney (Dec 11-14).