The trio posted 4-under-par 68s to take a one-shot lead over Hale Irwin, Hubert Green, Isao Aoki, George Archer, Don Pooley and Dick Mast.
Irwin, the winner of last year's event at Kaanapali Golf Club, collected five birdies and two bogeys Friday at the Turtle Bay Resort's Palmer Course on the scenic North Shore of Oahu.
Rain and wind gusts up to 30 miles per hour buffeted the course and helped raise the scoring average to 73.538, more than a stroke and a half above par. The 68s were the highest scores ever to lead after the first round of this event.
Mauney, who earned full playing privileges for the 2001 campaign by tying for second at the Senior Tour Qualifying Tournament last December, parred the first 11 holes before posting back-to-back birdies at Nos. 12 and 13.
Needing only a pitching wedge for his approach to the 452-yard, par-4 17th, Mauney knocked the shot to two feet for an easy birdie. He added a birdie at the par-5 home hole after blasting out of a greenside bunker to set up another two-footer.
'I'm a mudder,' said the former television sportscaster, in reference to his play in bad weather. 'Lots of wind on the front nine and then it rained hard on the back. I stayed real patient. The rain makes me focus more.'
Jacobs, who had a bogey at the second hole but made five birdies the rest of the way, earned his first lead after any round since the opening day of last year's Seniors Players Championship. He eventually tied for 30th in that major tournament.
Currently ranked 31st on the season money list, Jacobs sits squarely on the bubble for the Senior Tour Championship later this month.
'I want to get back in the Tour Championship,' said Jacobs, a three-time winner on the 50-and-over circuit. 'I've played in that every year.'
Gibson was floundering at one-under par after carding three bogeys and two birdies through 10 holes. He then reeled off three straight birdies from the 12th and tacked on two more at Nos. 16 and 18.
Tied for 10th place but just two strokes off the pace were Vicente Fernandez, Walter Hall, Graham Marsh, Frank Conner, Roy Vucinich, Kurt Cox and Bobby Walzel.
Click Here for Full-Field Scores from the Turtle Bay Championship.