Once the bewilderment wore off, they set to gutting it in the hope of keeping the meat.
"As soon as we gutted it and chucked all of that over, heaps of sharks came around and that was the end of the fishing," he said.
"We put up with the smell for a couple of hours, and in the end, I said, mate, we've got to chuck the rest over."
When they got back to land, Mr Dobbs kept the bizarre story largely to himself.
Later, many mates and work colleagues he did tell rubbished his yarn as porkies - even after being shown pictures he'd taken on his phone.
"Even my dad doesn't believe me. He will now."
The tale has captivated fishermen around the country.
By last night, pictures posted on the Whitiangler Facebook page had been shared hundreds of times.
Tournament organiser Stan Hill, who wasn't aware of the bizarre catch until phoned yesterday, said this was the first time he'd heard of a pig being caught at sea.
But many other Coromandel locals weren't so surprised - long-time pig hunter Mock Johnstone was aware of half a dozen such encounters.
"It happens now and again - if they are being chased by hunters, at odd times they'll take to the water and swim for their lives," he said.
"We actually chased one once at Te Kouma Harbour in Coromandel, and it jumped in one side and swam right across the harbour, for about half a mile, and got out of the water on the other side."
Champion spearfisher Darren Shields once came across one around half a kilometre off the coast of Whitianga.
"It had just drowned and was obviously worn out ... it was floating, it had a few dog bites on its legs and must have only just died," he said.
"It was not a common occurrence but it wasn't unusual that it happened every now and then - I remember a guy got a big boar once out off there, it was about 180 pounds and it was a long, long way out to sea."
Curly Tales
• 1947: A wild sow came ashore at Kuaotunu in the Coromandel after three hours in the sea, probably after being chased by a hunting party, according to Alaric Newbald who lived there at the time.
• 2007: Northland fishermen Carlo Jelas, Dave Martin and Hank Martinovich were in a boat near the old Marsden B power station when they came across what they first thought was a seal in the water. It turned out to be a live 140kg boar.
• 2012: Kuratau man Bob Monteith and a mate were fishing in Lake Taupo when they came across a sow swimming 200m offshore. "It's actually my son who's a hunter and he was not very happy that dad got the pig," he said at the time.