The fish – caught 180 miles offshore from Cabo San Lucas - was weighed on two different scales registering 427.5 pounds on one and 427 pounds on the other.
IGFA representative Minerva Saenz was present for the weigh-in and has sent off the scales to be verified and checked for certification.
No matter which weight is deemed the official weight, both would be a world record.
Mike Livingston of Sunland, California currently holds the yellowfin tuna record – a 405-pound brute caught on November 30, 2010 near Magdalena Bay, Mexico.
The two-year gap between the two recent records is surprising, given that Livingston broke a 33-year-old record, set back in 1977 by Curt Wiesenhutter.
For Yocom, however, there's more at stake than just a world record. The Californian is now in position to win $1,000,000 thanks to a contest he entered with Mustad.
In that contest, whoever lands the first IGFA All-Tackle World Record from the start of the competition (Oct.1 2011) with a Mustad hook from a select group of species wins a million dollars.
Seeing as how the contest closes at the end of September, 2012, after a year of no new world records, Yocom got his catch in just in time.
Being the experienced angler he is, Yocom brought the fish to the boat in less than an hour.
They boated the 180 miles back to Cabo San Lucas, finally getting to shore at 8:00 AM on Wednesday, September 19.
"Two hundred and twelve pounds is my previous record,” said Yocom in an interview with the Pisces Sportfishing Fleet, a local chartered fishing company, “but my son did get a 350 pounder on the boat last month".
Yocom caught his fish with a Shimano Tiagra reel and 100 lb test line.