The ski leg was the determining stage for Miller in making his move to crack open a winning lead.
"I just tried really hard to push away at the start of that board race cause I was not really keen on a sprint finish to be honest," he said.
"At the end of the day it is always going to be a bloody hard race. My tactic was to push the run and that was one of my strong legs. I needed a gap on the ski and the plan was to take a lead into the board, so I was pretty stoked how it worked out."
Miller found time to compliment his good friend Dempster who won the best beach sprint of the day to clinch second place.
"I am so stoked for Declan as well. Us young guns coming up, challenging the big boys. This is the start of it."
No Mount clubbie had won the event before which is a record club coach John "Spindles" Bryant was thrilled to see Miller break.
"I have been coaching him since he was 9 and he is just an unreal kid. He has a massive pump on him and just loves it. He gets in there, does the work and understands the ocean."
Aucklander Rachel Clarke won her first women's title at the event after taking out the world surf ski series just a week earlier in Australia.
The former New Zealand Ironwoman champion used her ski strength to pull away, then held off teenagers Ella Kingi (Lyall Bay) and Hannah Baker (East End) despite limited time on her board.
"I was sitting around after winning the world series and thought 'why not give the Monster a go?'. I've done it in a team before but never as an individual and managed to get my entry in about three hours before they closed," Clarke said.
"The run was pretty hard but once I got about a kilometre into the ski, I felt really comfortable."