BOSTON -- Emergency crews searched for a missing swimmer in Onset, fire officials said Friday.

At about noon Friday, a kayaker called 911 to say he saw a person jump from the Dummy Bridge and not resurface.

"The person reported that he heard splashing and when he turned his attention to the direction of the splashing, he saw someone go in the water and did not see them come up," Onset Fire Chief Howard Andersen said.

Dive teams from the Wareham, Onset and Carver fire departments searched the waters near the bridge for hours on Friday, but did not find anyone. At one point, there were 14 divers in the water.

Andersen said he has no reason to believe the kayakers call was hoax.

"It is my understanding that he is actually a firefighter somewhere in the state of Virginia. So I take that as a credible witness," Andersen said.

Anderson said he does not have a description of the swimmer and it was not even clear if the swimmer was a male or female.