Although the incident occurred in St. Martin Parish, Assumption Parish Sheriff Mike Waguespack said his deputies responded to the call.
Waguespack said 28-year-old Jacob P. Lewis, of Walker, and his wife went out Wednesday to scout areas to set crawfish traps.
The couple went back to their truck and Lewis backed the truck down to attach the boat to the trailer.
Waguespack said Lewis’ wife noticed the boat didn’t hit the trailer. She got out and saw her husband in the water.
Officials with the Baton Rouge Fire Department are assisting in the search.