Water floods the 18th green at the Bethpage State Park’s Black Course on Thursday in Farmingdale, N.Y. Play was halted during the first round of the U.S. Open and will resume today.

Farmingdale, N.Y. ? The first round of the U.S. Open started Thursday. The end is not yet in sight.

Making greens look like swimming pools and creating streams on many fairways, a daylong deluge overwhelmed an already-waterlogged Bethpage Black and postponed most of the opening round until today.

Rain that began moments before play began at 7 a.m., prompted a suspension at 10:16 a.m., and the United States Golf Association gave up hope for the day just before 2 p.m.

No one completed more than 11 holes, and half of the 156-man field didn’t even get started.

“Where’s my canoe,” mused Ian Poulter on his Twitter feed.

Oh, and while today’s forecast isn’t as bad, more rain is possible. And Saturday is expected to be much like what greeted players Thursday.

“I wish I had better news,” said Jim Hyler, chairman of the USGA’s championship committee.

In other words, this is no longer just a test of skill, but a test of patience, as well.

Already, there’s talk of a Monday finish, and not one like the classic playoff between Tiger Woods and Rocco Mediate a year ago at Torrey Pines. For the record, the last regulation Monday finish at the U.S. Open was 1983.

“They did the right thing,” said Jeff Brehaut, who left for the day in a four-way tie for the very early lead at 1 under through 11 holes. “It got bad.”

Conditions were arduous for everyone, including Woods, whose title defense started with an adventure.

Playing alongside fellow reigning major winners Padraig Harrington and Angel Cabrera, Woods’ first shot was so far off line he considered playing a second ball from the tee.

“Way left,” caddie Steve Williams said to the world’s No. 1 player on the tee box.

Woods eventually hit his second from near the front of a merchandise tent, his ball sailing over the thickest rough alongside the opening fairway. He ended up playing off grass trampled by several days of foot traffic, then got up and down from a greenside bunker for par.

So while Woods successfully salvaged his first hole, work crews — armed with squeegees on greens and using hoses to pump water off the 18th fairway — eventually couldn’t keep up with the rainfall.

Less than a half-inch had fallen when play was halted, but the already soggy course couldn’t take the extra moisture. And it wouldn’t let up, either.

“The volume of rain falling was outpacing our ability to squeegee the greens,” Hyler said. “That was the bottom line. The greens just became unplayable and we needed to suspend.”

Brehaut, Johan Edfors, Andrew Parr and Ryan Spears were the only players under par when play was stopped.

Woods was 1 over through six holes. When play resumes at 7:30 a.m. today, he’ll have a 10-foot par putt on the seventh green.

Cabrera, Poulter and Justin Leonard were among those at even par when play was halted. Other notables: Former U.S. Open champions Geoff Ogilvy, Jim Furyk and Michael Campbell were 1 over, Boo Weekley and Zach Johnson were 2 over and Harrington was 4 over.

Forecasters said all week that rain could have a serious effect on the tournament, especially during the first day.

They couldn’t have been more right.

Rickie Fowler, an amateur who made the cut at last year’s Open, was the first person to swing away from the opening hole Thursday. He arrived at the tee at 6:54 a.m.

It started raining two minutes later.

“There’s a long way to go,” Brehaut said.