California Highway Patrol officers got a call about the boat shortly after 6 a.m. Tuesday.
A total of six people were detained after they were seen walking away from the boat, but it remains unclear if they are connected to the panga. The individuals were taken into custody by ICE Homeland Security Investigations, officials said.
Authorities say there are no indications of drug smuggling.
The Ventura County Sheriff's Department is helping with the investigation.