Visible crew/equipment: After Truman sees his father as a homeless man there is a scene where he runs into a vehicle (before the dog runs past). This shot is from the ground looking up. Take a look at the reflection in the passing car, you can see the crew and equipment. (00:15:50)
Visible crew/equipment: When Truman takes his high school sweetheart to the beach, her "father" comes to get her. There is a shot through the father's button cam showing Truman backing away. Look at Truman's shirt and you will see not one but two human shadows. One is the father and the other is the "button" cameraman. (00:25:30)
Visible crew/equipment: In the scene at the travel agents when Truman is trying to book a flight to Fiji the woman asks 'when would you like to leave?', Truman holds up his suitcase and says 'today'. When he holds up his suitcase you can see the boom mic reflected on his suitcase. (00:41:25)
Visible crew/equipment: During the scene following the leak at the plant when Truman's wife is trying to ask him what is going on, she is standing next to a counter. Look at the farthest left door. A shadow of a crew member can be seen moving.
Visible crew/equipment: Right as Truman is leaving to go to Fiji in the sedan, he backs out of the driveway. The shot is a camera attached to the rear of the vehicle. The rig is reflected in the bumper on both sides of the license plate.
Answer: He'd been hoping the waves would discourage Truman and make him turn back. It's a lot easier to agitate water than it is to calm it, so by the time he saw it wasn't working, even if he's thought of that, it would have been too late.
Captain Defenestrator