BALTIMORE -- Maryland Natural Resources Police are investigating a brawl on board a crowded rental boat in the Choptank River over the weekend, an agency spokesperson confirmed to CBS Baltimore on Monday

Video of Saturday's incident, which went viral after a witness uploaded it to Facebook, shows two men -- including the driver -- come to blows and at one point one of the men can be seen swinging what appears to be the antenna at the other man.

Facebook user Daryl Newhouse, who was riding on the safety boat for the Cambridge Yacht Club Annual Fun Regatta, said at times the boat veered dangerously close to sailboats racing in the regatta. Those on board, whom Newhouse said appeared to be intoxicated, ignored calls from the safety boat.

Several people on board can be heard screaming over the commotion and can be seen trying to break up the fight. Those on board Newhouse's boat can be heard trying to warn the men that authorities had been called. At one point, someone wondered aloud whether the men were about to fall overboard.

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Natural Resources Police have spoken with everyone on board the boat, except for the operator, Natural Resources Police spokesperson Candy Thompson told CBS Baltimore in a phone interview Monday. Thompson said the group paid $3,000 cash for the damage caused to the rental boat.

Investigators still want to speak with the 21-year-old operator, who is from Crownsville, Thompson said. He faces a possible charge of negligent boating, she said, which carries a fine of up to $500 for a first-time offense.

This fight on the Choptank Saturday could have had deadly consequences. Charges pending: https://t.co/mwCvepDwF3 — MD NRP (@MDNRPolice) July 25, 2016

In a brief interview, Newhouse expressed disappointment that there wasn't a law enforcement officer present to witness any behavior that would have supported a BUI charge.

"I used to be a lifeguard at that age so I wanted to stay close enough to help if one went overboard," she said. "We tried getting their attention, directing them away from the sailboats and signaling to cut their speed but all six deliberately ignored us and started straight ahead despite our waving right next to them. Then they went through the finish line where our committee boat and mark were set up."