SOUTHAMPTON, N.Y. — Maybe he should have stayed on his dinghy.

Playing Thursday in his first U.S. Open in three years, Tiger Woods opened with an 8-over 78 that was tied for 101st in the 156-player field. He joined a sizable group of big-name players taken down by Shinnecock Hills’ unforgiving course and the eastern Long Island wind.

“I just didn’t get off to a good start today,” said Woods, who opened with a triple bogey and bogeyed No. 2. “I didn’t putt well. I drove it pretty darn good for most of the day. Just never really took advantage of opportunities.”

Woods turned his game around after the early stumbles, playing the next eight holes in 1 under. But he found a bunker with his tee shot on the par-3 11th and made a bogey, then four-putted from 40 feet for a double bogey at No. 13.

“I was worried about running the (first) putt by because it’s downhill on the other side,” Woods said. “Left it short. Blocked the next one, then blocked it again.”

His troubles followed him on the par-4 14th. Woods whacked his drive into the deep rough on the right side of the fairway. His second shot ended up in the rough outside the ropes on the left. He made a second straight double bogey to fall to 8 over.

“I felt good most of the today,” said Woods, who is staying in nearby Sag Harbor on his 155-foot luxury yacht, which he referred to this week as his “dinghy.”

“Just shoot something in the 60s (Friday), and I’ll be fine. I think today was the toughest day we’ll have all week.”

‘Silly’ season: Scott Piercy was one of the few players to make it into red numbers, shooting a 1-under 69 to share the first-round lead with Dustin Johnson, Ian Poulter and Russell Henley.

The Las Vegas native made an 80-foot birdie putt on the par-4 12th — “Obviously, the (putt) on 12 was kind of silly,” he said — and mostly managed to conquer the blustery conditions that did in other players.

“The first nine holes, it kind of died a little bit,” said Piercy, 39, who made only two bogeys. “Then when we made the turn, it picked back up.”

Piercy said his round stood in stark contrast to his practice round Wednesday, when he said he walked off the course after four holes.

“I was skanking it, and I lost like five balls in the first four holes,” he said. “I’m like, ‘I’m outta here.’?”

Back to back? Johnson is looking to make history this week after winning the St. Jude Classic on Sunday in Memphis, Tenn. No player has ever won the U.S. Open after winning a PGA Tour event the previous week.

The 2016 Open champ holed out from a bunker on the par-4 eighth for one of his four birdies. Two holes earlier, Johnson’s tee shot landed in deep rough, and a large pack of people, including playing partner Woods, searched for the ball for several minutes. Finally a TV crew member stepped on it.

“There was a guy standing there who watched it bounce in there, and he just stood on the hill and waited for all of us to come up,” Johnson said. “You would think he would at least mark the spot where it was. It probably should have never come to that, but, yeah, it was nice for him to find my ball.”

Rank and vile: After topping his drive on the eighth hole, Garrett Rank was able to regroup and make one of his nine pars in an opening 83 for the NHL referee and Open qualifier. Rank, 30, who is also a cancer survivor, said he “tried to enjoy” his time.

“It’s just cool to be out here,” he said. “I obviously wanted to play better, but at the end of the day, I’m at the U.S. Open, playing in a major championship.”

Tiger groupie: Scott Gregory said he would “forget pretty quickly” his unsightly 92 — the first score in the 90s in a U.S. Open since 2002.

But whatever transpires the rest of the way for the 23-year-old Brit, he won’t leave Shinnecock without a notable keepsake. The 2016 British Amateur champion had his photo taken with Woods this week.

cred@nydailynews.com