Game wardens are reiterating their plea for snowmobilers to use caution on thinning ice after a snowmobile plunged into Maranacook Lake in Winthrop on Friday.

Game Warden Steve Allarie said the man and a teenage boy who were riding the snowmobile managed to get out of the water without injury, but the incident serves as a reminder that the changing season means riders must be extra diligent to check ice conditions.

“Conditions are going to change rapidly due to the increase in air temperature,” Allarie said. “Please test your ice before you go out.”

Friday’s accident occurred around 3:30 p.m. under the train trestle that crosses a narrow section of the lake between Campers Point Road on the west and Greene’s Way on the east. The driver and his nephew were riding south toward Winthrop when they went through the ice.

“The operator, who was not familiar with the area, saw a track and followed the track and unfortunately went through,” Allarie said.

The man and boy, neither of whom was identified, made it to shore and called a family member, who picked them up.

Allarie, who checked the area Saturday to make sure the submerged snowmobile was leaking no fluids, said the section of lake underneath the trestle is notorious for thin ice.

On the day of the crash, the ice was covered by snow, but by Sunday morning there was a section of open water, prompting Allarie to drape yellow caution tape across the narrows.

“Typically it does not freeze,” he said. “It always has that thin coating of ice, but never truly freezes hard.”

David Sinclair of Sea Ventures Charters of Wayne, which was hired to recover the snowmobile from the lake, said he has pulled a half dozen machines from that section of water over the past several years.

The ice Sunday was nearly 2 feet thick less than 100 feet from the hole where the snowmobile went through.

Ice in the northern end of the hole was 6 inches thick, but in a span of about 15 feet shrank to just an inch in thickness in the southern end.

“That’s how people get in trouble,” Sinclair said. “It looks the same on top. We’ve been here a bunch of times.”

In 2013, two snowmobiles went through the ice in that area, Allarie said.

“The real problem lies in that the local residents know that it’s open and they skim across it, year after year, because it’s a shortcut to go towards the north,” Allarie said. “The trail takes a little while to get around.”

Sinclair recalled a salvage job at the site years ago when a group of snowmobilers came through the area at about 80 mph. The riders knew the section was open water and decided to skim across to the good ice on the other side.

Recovering the snowmobile Sunday required a winch, anchored by a hole drilled through the thick ice, which powered a cable strung over a tripod made of angle irons that was set up at one end of the large hole in the ice.

Sunday’s recovery took less than an hour once the equipment was in place. Sinclair’s son, Matt, dove through the hole and located the snowmobile several yards south of it.

“The biggest thing is to find the vehicle,” David Sinclair said. “Usually with an ice job there’s a reference hole.”

Matt Sinclair tied a rope to the machine’s two front skis. Within a few minutes, the winch had powered the skis out of the water and onto the ice. The crew unhooked the drive belt to tow the snowmobile back to shore where it could be loaded onto a trailer and taken to a mechanic.

Sinclair warned that longer days and rising temperatures in March will make ice much more unpredictable throughout the state. This was the first snowmobile Sea Ventures has recovered this year – several weeks ago they removed an all terrain vehicle from Jaimie’s Pond in Manchester – but he said he fears things are about to pick up.

“It’s been quiet lately,” he said. “Hopefully nobody will get hurt before the end of the season. We don’t mind pulling the machines out, but when somebody gets hurt or dies, that’s not fun.”

Even though most lakes and ponds have a good layer of ice from the cold winter, the heavy snow received throughout the state this year can push the ice down, which pushes water on top of the ice where it freezes.

That means the ice is very inconsistent, Sinclair said. There could be layers of ice, slush and water. “It’s deceiving to look at up on top,” he said.

In the past, Sinclair has had to recover machines used by ice fishermen who followed their typical track out to their shack in the morning and then went through while following that same track back in the afternoon.

“That’s how much things can change,” he said. “Just a little softening, things get weaker and the current’s working underneath. It can get you. It’s not like people are out there trying to cause trouble or anything. You just get caught.”