ONALASKA, Wis. -

Despite two water rescues in the last two weeks that both turned out to be false alarms, authorities say people should never hesitate to call 911 if they see something suspicious.

"I don't see that being a waste of resources," said Onalaska Fire Chief Don Dominick.

"I think it's great in this time and age that people don't just neglect it," he added.

Onalaska firefighters, along with the Campbell Fire Department, Brice Prairie Fire Department, and the La Crosse Dive Unit, spent 2 1/2 hours Friday night searching Lake Onalaska. The search came after two long-time residents reported a flashing light they thought might be a boater in distress.

"Not only was it flashing but it was intermittent, like someone was trying to signal them," said Dominick.

No distressed boaters were even found.

The weekend before, crews spent several hours searching the Mississippi River after a truck driver reported what he thought was a tipped over canoe near the I-90 bridge. That search also turned up nothing.

"It's a little bit frustrating but I would rather do that then read in the paper the next morning about a boater who's been missing for two days and nobody even called it in," said Kevin Kappauf, the training officer for the La Crosse Dive Unit.

The all-volunteer organization was involved in both recent water rescues.

Kappauf says the least reliable tips usually come from people driving through the area.

"We ask that you stay there. If we show up and somebody drove by (and left), we have no idea what the person is talking about or where to look," said Kappauf.

Both Kappauf and Dominick say the only thing they can do is use the false alarms as live training opportunities.