Surf Life Saving Northern Region operations manager Alan Gibson confirmed to Stuff lifeguards attended a neck injury incident at the surf beach that day and several were called to the scene where they immobilised de Mari's spine.
The Italian sailor was transported by ambulance to Middlemore Hospital in Auckland where he spent the following week in their high dependency ward in a serious but stable condition.
De Mari sailed for Prada Challenge in the 2000 America's Cup and remained with the team in 2003 and 2007 after they were renamed to Luna Rossa.
He then joined Oracle Team USA on their America's Cup winning campaign in 2010.