"They (TNZ) started with hydraulic buttons on the wheel.
"They went from Dean doing it on the wheel initially when they launched. Then I think (strategist) Adam Beashel did it. The systems were very, very similar except they decided to use a dedicated person to adjust it where we set ours up so the helmsman could do it. There were pros and cons both ways."
There was nothing secret or underhand about Oracle's foiling system, which relied on human grunt, he said.
"There is no secret system. You need guys to wind rotary pumps that move oil, then you press the button - it opens the server up.
"They had the same thing. It's a big hydraulic ram that folds and adjusts the foil. You are like a pilot adjusting ailerons.
"You can press the button all day but if someone is not turning and moving oil for you it is not going to do anything. You need hydraulic oil because the pressure is high and the loads are so high."
Both boats had been extremely similar, with Oracle's dramatic improvement down to plain hard work, Spithill said.
"It was just about the sailors figuring out how to sail these boats. It was so new to us. We are only scratching the surface with these boats.
"So the steps if you could make a jump, were massive. They made a huge jump at the start. But then we were able to step over them.
"That came down to hard work and just hours on the water."
Oracle had practised every day off and reserve day while Team New Zealand had chosen to rest, he said.
Sir Russell Coutts drove the turnaround, insisting Oracle strive tirelessly for improvement.
Smaller, cheaper boats would likely lead to more entries for the next Cup but the boats would be just as fast and every bit as spectacular as the massive AC72s used in the last regatta.
Spithill indicated he would almost certainly remain with Oracle despite the emergence of an Australian team as challenger of record.
"(Oracle team owner) Larry Ellison has been a mentor and really good mate for a long time now. And Russell Coutts has just been awesome to work with. I can't see myself leaving. First and foremost I want to win.
"I want to be competitive and I want to do it with a great team. We want to do a three-peat. That gives us a lot of hunger and motivation."
Spithill said he couldn't imagine an America's Cup that didn't involve Team New Zealand.
"You've got to be pushed by the best to make you better. That's what happened with us. We took on the world's best team. You can't conceive of the America's Cup without Team New Zealand. It would be like having a Rugby World Cup without the All Blacks. You just think there's no way."
While he hadn't caught up with Barker since the regatta, he hoped to over the next couple of days to "go for a beer up the road and catch up".
