KEY POINTS:
Two Australian kayakers on the final leg of a transtasman journey have hit the most dangerous part of their voyage.
Last night the pair were 130km off the coast of New Plymouth and entering shipping lanes without the radar transponder necessary to ensure that big cargo ships have a chance to spot their tiny craft.
James Castrission, 25, and Justin Jones, 24, expect their custom-built kayak, Lot 41, to arrive on January 13, exactly two months after leaving Forster, in New South Wales.
The kayak's name comes from the Trentham sales catalogue entry for New Zealand's most famous transtasman export: Phar Lap.
Their electronic Comar transponder stopped working about December 6, and the two have only small navigation lights to warn ships of their presence.
"They're approaching the coast without a Comar unit - this is probably the most dangerous time for them," said Tom Mitchell, a spokesman for the pair in Australia.
It would be safer to have a transponder, but the men did not want a replacement delivered to them in case such help invalidated their claim to an "unassisted" voyage.
A spokesman for Maritime New Zealand said it was not required to advise shipping of the kayak's presence and very few other small craft carried transponders.
"However, given the small size of the kayak and the potential difficulty of seeing them from a ship, we would advise ships of their presence if we were aware they were going to pass nearby," the spokesman said.
The kayak has a GPS tracking device, and Maritime New Zealand could also track ships fitted with automatic identification systems and warn them when they approached the kayak.
The Rescue Co-ordination Centre is monitoring the kayak's progress.
Though the two men are about 1960km from their starting point they have paddled more than 3000km so far, weaving an erratic path across the Tasman.
They have battled swells as high as 10m and days of headwinds and ocean currents which were at times so strong they shut themselves in the kayak's coffin-like "cabin" and put out a sea-anchor because there was little point in paddling.
At one point, a mid-Tasman eddy of the East Australian Current carried them in a big loop which took them back to where they had been 10 days earlier.
Altogether, the headwinds and currents are estimated to have forced them to paddle more than 800km further than planned and added more than two weeks to the voyage, which they hoped to finish at Auckland before Christmas.
The pair are travelling at a little over 3km an hour, but have said on their website they are so physically and mentally exhausted that they are losing their sense of direction.
Jones said in a podcast on their website that he and his partner were losing mental focus and their leg muscles were wasting.
Their bodies' fat reserves were thought to be heavily depleted.
"We'll get our east and west mixed up and can't remember numbers we were talking about just an hour ago," he said.
"We're just getting worn down slowly.
"Fifty-seven days is quite a long time to be in a small little kayak out on the Tasman Sea ... our bodies have definitely wasted away quite significantly," Castrission told the Seven Network in Australia.
And speaking by satellite phone from the kayak, Jones told Australia's Nine Network: "Our bums are really sore and our muscles are starting to get really fatigued.
"Day by day, it's the physical fatigue that we're going through and the fact that our minds are not as sharp as they used to be," Jones said.
"We're busting out 30km, 40km, 50km a day and at the moment it's just bleak weather. The sea's grey and it's rolling in and blending into the sky, which is grey. Everything's grey."
They have one dehydrated meal a day, and have to use a manual pump to produce drinking water.
- NZPA
