Earl, from Cromwell, teamed up with three-time Longest Day open women's champion Emily Miazga and former world champion rower and 2008 Olympic bronze medallist Nathan Twaddle.
They entered the three-person team section under the name Beer and Cookies.
Earl and Twaddle tackled the cycle and kayaking stages respectively, while Canadian Miazga added her international multisport experience to the alpine run.
Sporting pedigree does not come much better than this team. Earl's biggest supporters are his wife, Georgina (nee Evers-Swindell), a two-time Olympic double sculls champion, with twin sister Caroline.
Earl's father Athol was a member of the gold medal-winning 1972 Munich Olympic rowing eight.
Earl managed a triple roll as he approached one of the bridges on Saturday.
''I left it all out there. I got a standing ovation for that,'' he said.
The three formed a team that captured the spirit of the event, with Miazga donning a bikini to join Twaddle for the run down the finishing chute.
''This is an awesome event,'' Twaddle said of his first experience.
''The beauty of doing stuff like this is that if you get sick of doing one form of training then you can always go and do another.''
Earl, who competed in the two-day individual section last year with mixed fortune, joked with Twaddle at the finish about getting in better condition for another crack next year.
''I wasn't going to do it this year, until I found out at Christmas time,'' Earl said of his call to arms from Twaddle.
Fellow rowers Mahe Drysdale and Joseph Sullivan - who both won gold at the London Olympics - competed in the Longest Day section.
Earl was able to train on the river with Drysdale and Sullivan on Thursday, as a precursor to Saturday's race conditions.
''It was pretty low. I'm not the lightest fellow, so I'm conscious of needing a bit of buoyancy,'' Earl said.
Earl's team finished seventh overall and second in the mixed team category in a time of 12hr 53min 51sec.
Drysdale and Sullivan plunged straight into the Longest Day event, rather than opt for the slightly easier two-day version.
The Coast to Coast came in the middle of a six-month sabbatical from top rowing for Dysdale, but for Sullivan, it was just one week out from the national championships.
Another competitor in the two-day section taking time away her day job was Auckland Central MP Nikki Kaye, who by her own admission was ''high on experience in falling out of the kayak''.
''I marooned a couple of times.''
Kaye said she was overawed by the amazing stories behind the people involved in the race.
In the lead-up to the two-day individual challenge she was able to wind up her Cabinet colleagues, Bill English and Nick Smith, who had previously taken the ''soft'' option of competing in the team section.
