“It’s something I thought I could do,” he said. “It’s a challenge and I can raise some money for cancer by doing something that people will notice.”

He is planning the 17.4km swim from Cape Jervis to Penneshaw on Sunday, November 18, when a dodge tide will mean the normally strong currents will be at their weakest.

Backstairs Passage is the infamous stretch of water between the Fleurieu Peninsula on the mainland and Kangaroo Island.

It was named by explorer Matthew Filnders after part of a courthouse. It measures 14km at its narrowest point. 

No stranger to long-distance ocean swims, Mr Sanigar successfully swam the 40km English Channel from his native England to France in July 2013.

The 36-year-old has since moved to Kangaroo Island and lives in Baudin Beach with his wife and two children.

He has decided to donate money raised from the swim to the Australian Cancer Research Foundation and donations can be made at his ACRF page.

“Cancer is something that seems to affect just about everyone,” he said. “It has affected people I work with and people close to me so cancer research is a very worthwhile thing to raise money for.”

He has calculated the swim will take between seven and nine hours, a shorter time than his 13-hour Channel swim.

He plans on leaving from the shore adjacent to the Cape Jervis boat harbour at about 8am, swimming directly across to Penneshaw Beach, hopefully arriving before 4pm when the tide is supposed to kick back in.

He will swim a similar route to the ferry and has contacted SeaLink to let them know of his intentions.

Kangaroo Island waters are known to be shark habitat but unlike a previous Passage swimmer he does not plan to use a shark cage.

Instead the Ocean Guardian company has kindly agreed to make available one of its Shark Shield Freedom 7 devices, which will be towed from a buoy alongside him.

Neither is he going to use a wetsuit, instead slathering himself in Vaseline and Bepanthen nappy rash cream to prevent chafing, a trick he learned from his channel swim when he thought he would use his then baby’s rash cream.

He has been training regularly for a year, although he admits not to the extent he did to prepare for the Channel swim.

He has been swimming laps of the Kingscote ocean pool and then for a more realistic ocean feel, along the wave line at the main Penneshaw beach.

He has assembled a small support team, including 17-year-old Jakob Zeman, with whom he works at the Penneshaw IGA supermarket.

Jakob will be his support swimmer jumping in and helping Mr Sanigar reach his swimming rhythm, but by the end of the swim he reckons the youngster might have swum about half the distance.

He will also have a support boat and fellow KI resident Paul McNally, whom he met dropping the kids off at the school bus, has agreed to drive his boat alongside the entire swim.

Fellow Kangaroo Island residents Philip Baines, Jeff Turbill and Chris Porter have agreed to be support crew on the boat, while Penneshaw Fuel & Hardware has donated the petrol for the support boat.

Penneshaw IGA will supply the Vaseline and rash cream, although they won’t be supplying his food, as he has own special maltodextrone-based food supplement, that he will be taking in every half an hour.

He estimates he will be burn up to 7000 calories on the journey, swimming and battling the cold. 

“It’s all about working on your technique and falling into a rhythm when you’re swimming distances,” he said. “You need to maintain that rhythm and its not about sprinting or pushing yourself. Within 20 minutes things should fall into place.”

This is not the first swim across to Kangaroo Island.

According to Wikipedia, the first recorded solo swim across Backstairs Passage took place on June 6, 1995 when South Australian marathon swimmer Andrew Martin covered 14.25km distance in 4 hours 31 minutes 30 seconds.

David Falland from Nuriootpa then successfully swam Backstairs Passage back in 2005.

And according to reports at the time, he swam 35 kilometres to cover the 18km distance because of the tide - not something Mr Sanigar wants to emulate. 

Mr Sanigar said he understood Mr Falland used a cage and a wetsuit for his swim.

There are also reports of much earlier attempts to swim Backstairs Passage by a Thomas Morris of Sydney.

The Border Watch newspaper in Mount Gambier on January 7, 1933 reported that Mr Morris had to give up “three quarters of mile from his goal as a result of rough seas after he had been in the water for six hours.”

Mr Morris however was swimming in the opposite direction to the mainland and the article indicated he had failed previously. 

The modern-day swimmer Shane Sanigar has accurate weather and tide forecasts to use and that is why he chosen the day of least tidal flow, or a dodge tide.

He is however at the mercy of the weather, and should the trip need to be cancelled due to unfavourable conditions he said the team is committed to another attempt at the next available dodge tide when everyone was available. 

The Islander