Deep into the Woods
At the opening of the film we watch as the men drive deep into the woods to what appears to be an abandoned mountain city. The symbol is that these city boys are completely out of there element the deeper into the woods they go as they lose sight of paved roads and the ability to navigate the density of the backwoods.
No Insurance
Lewis tells Ed he doesn't believe in insurance after talking about Bobby being an insurance salesman. The symbolism in Lewis not believing in insurance is that he would rather take the risk. He needs the feeling of knowing that what he is choosing to do has great consequences. It makes him feel alive, and it also makes him a liability to the other men who play life far more safely.
Gun Rack
When the guys enlist the help of the mountain men to drive their cars to the river, we see one of the hillbillies put a rifle on a gun rack in the truck. The symbol here is that these men live outside of the law. They operate in a way that is right or wrong only to themselves.
Release
Ed gets up early after the guys' first night of sleep in order to go hunting. He has a deer in his sights with his arrow pulled back when he begins to shake. The symbol in this moment is that though Ed comes on these "man" trips he doesn't desire to kill, to do what is necessary in order to survive in the wilderness of the mountains as he just is not built in this way.
Peering
After burying the first hillbilly who raped Bobby, the guys get back into their canoe to head down the river. We watch as on screen we see the camera peering behind the trees out towards the men on the river. It symbolizes that their battle is not done, that they have more men to face who are going to come after them, now that they've killed their friend.