with an emphatic victory at Perth's Scarborough Beach.
Eckstein's younger brother Caine, a five-times Coolangatta Gold champion, made it a family affair on Sunday when he pulled out all stops to win silver and produce the first 1-2 result by brothers in the history of the event.
Rising star Dane Farrell won bronze.
Eckstein opened up a narrow lead after the 240m swim before extending his lead on the 340m board leg and paddling away on the 440m ski leg to boost his claims to being Australia's greatest ironman - a status Hendy himself has conceded.
In the women's event, Liz Pluimers realised a long-held dream when she won her first national title ahead of Harriet Brown and former Commonwealth Games swimming gold medallist Rebecca Creedy.
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Defending champion Courtney Hancock finished 11th.
Earlier, Pluimers showed her form by winning the open board event.
Naomi Flood scored a runaway fifth gold medal in the open women's single ski event from fellow Olympian Hannah Davis with Hannah Minogue (Bulli) taking bronze while Lachlan Tame claimed his fourth straight men's single ski title.
In the taplin relays, national champion club Northcliffe claimed the double - the men winning from Mooloolaba and Newport and the women's winning from Manly and Marchydore.
Northcliffe were crowned national champions with a record 474 points to Manly's 181 and Mooloolaba's 159.
