HARRISON TOWNSHIP, Mich. -

Rescuers are searching for a 33-year-old Shelby Township man who went missing Monday in Lake St. Clair.

Macomb County Sheriff Anthony Wickersham said the man went in the water after a woman fell off a boat as it headed back to shore.

Related: Divers find body of missing swimmer at Stony Creek Lake

The man, Julian Martinez, went under the water but never resurfaced.

Julian Joseph Martinez

Investigators say Martinez was on a boat with friends when one woman pushed another off as a joke. The woman who fell in the water could not swim. Martinez jumped in after her, helping her get back into the boat. However, Martinez never came back up.

A dive team was searching Tuesday morning.

"As long as there isn't lightning, they'll be out there," said Wickersham. "We've got a strong wind but, again, they've got a good location and we'll be able to put those divers in."

Family members say Martinez is a good swimmer, so it's surprising that he would go under.

Lake St Clair missing person search