ANTIOCH, Calif. -- Hoax May Day and distress calls involving alleged boating incidents on the San Francisco Bay has cost the U.S. Coast Guard a staggering $3.5 million so far this year, the federal agency announced on Thursday.

Using the busy Fourth Of July boating holiday as a backdrop, Petty Officer Kevin Neff said that such calls have accounted for roughly half of all the responses the agency has made so far this year on Bay waters.

“Not only is it a drain on taxpayer money, but it is also a drain on our resources,” Neff said. “The time we are using to respond to a hoax May Day call or someone firing a flare, is time we cannot respond to a real emergency.”

As an example of the costs, Neff said that one hour of flight time for a Coast Guard helicopter runs in the range of $8,000.

Neff said that such calls are a felony and can be punishable with up to six years in prison and restitution to the Coast Guard.

The Coast Guard said it was not unusual for children playing with a boat radio to send out a distress call. Neff said the boat operator can be held liable for such calls.

“We get calls frequently from kids who find the radio and call out help or May Day,” Neff said. “We are required to response to all calls like that…It’s like calling 911 on land.”