Sailing news site Yachtingworld said solo sailor Ruyant's boat is "cracking like an egg shell and splitting apart". They reported that the 35-year-old Frenchman sent them photos of the damage caused when he hit what he thought was a shipping container on December 18.
He is now trying to motor 420km to Bluff. Yachtingworld said he admitted he was not sure if he would make it.
Ruyant was sailing around the world single-handedly as part of the Vendee Globe yacht race, which started on November 6.
His Imoca 60 yacht, Le Souffle du Nord pour Le Projet Imagine, crashed into the object in the water with what he described as "an exceptionally violent" bang.
"I was at 17-18 knots and came to a sudden standstill hitting what was probably a container, seeing the damage it has done to the hull.
"The whole of the forward section exploded and folded up. Luckily the boat was not dismasted.
"I was sleeping on my beanbag and fortunately I had my head down in that, as I ended up hitting the mast bulkhead. I found things that were stowed in the stern right up against the forward bulkhead. They got thrown 10m forward."
Ruyant lowered the mainsail and started motoring but the damage at the front of the boat is spreading.
"The hull is opening up and the frame coming away a bit everywhere," he said.
"I'm sailing to the south of New Zealand. I'm not sure if it will all stay in one piece until then. What's good is that I'm in helicopter range, which is reassuring. I just have to push a button and they'll come and get me. The inside hasn't been affected and with my watertight doors, I'm sheltered."
Ruyant believed he was in a shipping lane between New Zealand and Australia, which may be why he hit a shipping container.
"I'm not far from the coast and I think I must be close to a shipping lane, which is perhaps the cause, as I have seen several cargo vessels. It must be the shipping lane between New Zealand and Australia. Given the seas down here, there are probably several containers in the water. I think that is what I hit given the violence of the crash.
"[It has been] a nasty Vendee Globe. It's over. I got halfway around the world. I'm upset that it has come to an end like this. I've had my share of problems. A lot of problems, but this one, I wouldn't wish on anyone."
Met Service meteorologist Tom Adams said the winds off the coast of Fiordland are the strongest in the country today. Rounding the bottom south west corner of the country will see Ruyant weather winds of 50km/h and gusts up to 65km/h. These will get stronger once a northerly front hits tomorrow pushing winds over 100km/h and gusting up to 130km/h.
"If he is trying to get through to Bluff he will have to go through that river of wind at some point."
Ruyant has already faced difficult weather when he sailed around south Tasmania.
A Rescue Coordination Centre spokeswoman said they were in radio contact with the skipper but he had not asked for assistance yet.
"He has significant damage but I'm not sure exactly what it is.
"I understand the hull has a split in it. He was pretty unlucky."
Ruyant's collision is the fifth time that a Vendee Globe competitor has struck a floating object and been forced out of this year's race.
