CANANDAIGUA, N.Y. (WROC) — Crews are searching for a man who investigators say presumably drowned while swimming in Canandaigua Lake Friday.

According to the Ontario County Sheriff’s Office, two men were on a boat around 1:40 p.m. when one of them jumped off to swim and began to struggle. The man was not wearing a flotation device, and the person on the boat attempted to toss one to him.

Sheriff’s officials called it a recovery mission Friday night. They said crews using sonar equipment found a “target of interest” around 7:30 p.m., but divers will be needed to investigate further due to the depth of that signal.

Those resources will be brought in by Monday morning.