The deaths of two men who drowned when they tried to cross a sandbar at Western Australia's popular Penguin Island were avoidable, a coroner has determined.



Pavan Kumar Ganasala, 37, and Praveen Kumar Pagadala Shiva, 31, died on December 28, 2010, when they tried to walk across a sandbar between Penguin Island and the mainland at Mersey Point in the Shoalwater Islands Marine Park.



Handing down his findings on Monday, Coroner Dominic Mulligan said the pair had ignored or misinterpreted warnings against making the journey by foot.



He said the Department of Environment and Conservation had also failed to close the sandbar following several rescues earlier in the day.



The public can access Penguin Island by private boat, ferry or by walking across the sandbar, but the DEC advises against walking.



The men had caught the ferry over but decided to walk back to the mainland with their wives, despite being advised by island staff not to, because they had seen others do the walk, the court heard.



As they veered into deeper water, the men tried to assist their wives by keeping them above water, as none of them were strong swimmers.



A DEC marine ranger in a dinghy collected both women and one of the men but could not get the other into the boat.



Instead he tied the man to the boat and made his way to shore where both men received CPR but died at the scene.



Mr Mulligan said if it were not for the ranger, who was not a lifeguard, the women would have drowned too.



The coroner said it would be difficult for anyone, especially those unfamiliar with the sandbar, to get back onto it once they moved off, due to winds and the current.



The inquest had heard 200 were people rescued every year from the sandbar.



Mr Mulligan noted the DEC had made some changes since the incident, including using lifeguards and tightening rules about when the sandbar should be closed.



The coroner's recommendations included that the DEC enlist Surf Lifesaving WA to do a risk assessment of the area and provide ongoing instructions to marine rangers.



He also recommended the DEC provide adequate resources for those involved in rescues and resuscitations.



Mr Mulligan expressed his condolences to the families of the victims.

AAP