BROOKFIELD, Conn. (WTNH) – The Connecticut Department of Energy and Environmental Protection (DEEP) is looking for the public’s assistance as crews continue searching Candlewood Lake for a man who went under on Sunday night.

Wednesday marks day four in what is now a recovery effort. Connecticut Environmental Conservation Police Captain Keith Williams said multiple agencies are looking for a 24-year-old man from Bristol. His identity has not been released.

Williams said the man was with a group of friends on a pontoon between 4:20 and 5 p.m. on Sunday. Officials are not sure if he fell or jumped off the boat, but they say he did not resurface.

It has been reported to investigators that he is a strong swimmer.

“We’re not sure if he intentionally jumped off the boat, or dove off the boat, or fell off the boat. We’re still trying to put those pieces together at this time,” Williams said.

Officials spent several hours searching for the man on Monday and Tuesday and resumed their search Wednesday. Brookfield police’s dive team initially searched for him on Sunday night and used sonar technology as well.

DEEP is now looking for assistance from anyone who was around Brookfield Bay on Sunday between 5:30 and 6:45 p.m. They are asking anyone with information to contact DEEP EnCon Police at (860) 904-8154.

Williams said this is an active investigation and they are looking into any and all factors, including if alcohol was involved and cold water temperature.

“It’s been a hard time for those people on the boat with him. Apparently, they were friends and coworkers so we’re trying to give them time […] but hopefully, we’ll have all the information we need,” Williams said.

Connecticut Environmental Conservation Police also say this underscores the importance of water safety.

“Know your limitations before you go out on the water. Know your abilities as a swimmer. Know the conditions before you go out,” Williams said.

Ryan Slater grew up on Candlewood Lake and is a DEEP boating instructor, teaching boating safety for 14 years. He stressed the importance of life jackets and staying hydrated and sober while boating to avoid another tragedy.

“These things can happen, they do happen. As we found out in the last couple of weeks, it certainly can happen to anybody. It’s just doing the right thing to prevent these things,” Slater said.

He also advises his students to keep an eye on each other.

“I really stress the buddy system, you’re never going to be alone in the water. It’s almost like when they teach young kids how to swim. You shouldn’t be alone, even if you’re 50 years old, 60 years old, or 70 years old. You should always have someone nearby watching over you,” Slater said.

Just a few days ago at Candlewood Lake, a man was pulled from the water and pronounced dead after he was working on his boat.

Steve Belida and Gwen Arment noticed a flurry of activity on Candlewood Lake Sunday night.

“We’re hoping it’s a good ending […] but of course, it’s hard to get there. Hopefully […] we’re heartbroken for the families,” Belida said.

Stay with News 8 for updates.