I run through the locations and as soon as I get to the location where the gun is installed on the boat, I can't pass through the wall with the help of a barrel or a coil, I just jump on the spot with it and that's it. Help.
The trick you are trying to do is called quickclip. As Nikitos mentioned, you need to do a trick called yesclip to be in a glitched state which allows you to do any quickclip. Here are two places where you can do yesclip in:
Current route, but difficult, since you cannot save delete at any point to keep the quickclip state, and the goo tunnel is quite hard for beginners:
Older, but easier route:
It has recently been discovered that the commonly used speedrun package referred to as the "5135 Unpack" has made changes that grant its users unfair advantages which were never present in any vanilla version of the game.
In light of this discovery, We've released an update which fixes these is
