"I admit that. I certainly didn't expect this to happen."
Mr Sommer raised the alarm just after midnight when his 9m yacht hit rocks at the entrance to Whangarei Harbour.
He had just purchased the vessel and spent time in Auckland with the previous owner familiarising himself before he set off.
"This is my second yacht. I bought a small yacht and learned to sail, joined the yacht club and took a lot of advice, and I worked my way up to a bigger yacht," he explained.
After he set off for Whangarei, things began to go very wrong.
"Yes, I made some mistakes but a whole lot of circumstances went against me."
"My plan was to stay at Sandspit for two days but the engine broke down. I made the decision to sail through, that was my biggest mistake," he said.
"It took twice as long as I thought it would, I struck a storm. "I was in the yacht being thrown around like the inside of a washing machine," he said.
He got into his dinghy and floated for four hours before he was rescued. He suffered bruising, severe hypothermia and was very dehydrated.
Coastguard spokeswoman Georgie Smith says the elderly man is lucky to be alive after he was plucked from the water at about 4.30am.
She said Coastguard volunteers responded to Mr Sommer's distress call but were unable to find him, or his yacht, at the location he gave.
For two hours, rescuers searched the shoreline between Reotahi and Urquharts Bay, at Whangarei Heads.
"Once the area had been covered by Coastguard volunteers on Circa Rescue and Refinery Rescue it was becoming clear the yacht was not in the location first advised," she said.
Mr Sommer, who was in constant communication with them on his cellphone, told them he had hopped into his dinghy and motored up a channel where he had hit a sandbank.
"As the conversation with the missing person continued, he advised he was not on a sandbank but was now walking on dry sand.
"He indicated he could see lights at a bach and was instructed to go to that bach and ask the people inside to call 111."
Mr Sommer's path was then obstructed by a deep estuary and, despite being advised not to, he got back in his dinghy and returned to the water.
Ms Smith said at that point all communication was lost.
Surf Life Saving volunteers eventually found Mr Sommer in his dinghy well south of where he thought he was.
He was was not wearing a lifejacket when he struck trouble, did not have a VHF radio and was not carrying flares, said Ms Smith.
"Should a flare or Epirb (emergency position indicating radio beacon) been available this would have significantly reduced the search time from a four-and-a-half hours search that very nearly cost someone their life," said Coastguard duty officer Mark Leevers.
"We just can't stress enough the importance of taking and wearing your lifejacket when out on the water. Things can happen in an instant and by wearing your lifejacket you're giving yourself the best chance of survival."
Mr Sommer agreed that he made mistakes.
"I express my regret for some of my decisions. I should have been more prepared for the trip and I wasn't. I put my hand up and accept the fact," he said.
He had planned to refit the yacht with full safety gear and technology so he could live on it, which is why he was sailing home to Whangarei.
"I was on my own, I also shouldn't have done that."
Mr Sommer wanted his ordeal to be a lesson to all boaties.
"Even with experience you can still get caught out. That is my message. I don't care how experienced you are, don't be complacent."
Mr Sommer wanted to thank the Coastguard, Surf Life Saving and Search and Rescue volunteers and police who helped in his rescue.
"I have a lot of respect for them. The support I have had from [them] and my family and friends has just been outstanding."
- Additional reporting Lynley Bilby
