Starting with the first Theory we venture to level 3, Plantation House. This one concern's several area of this level guide. First is at the construction site
So as you can see the devs have you go through this effort to get a long piece of plywood but then nothing, we immediately go to the bit about the plantation fields. Next we jump to the shoreHowever, there is something for the player to do here - an extremely long piece of plywood (part of a form) extends horizontally from the top of the last monorail support. In this case, the player can get at it by dragging crates from their nearby position to make a stack next to the portable toilet or construction office, climbing up on top of the trailer, and using something suitably long (like a piece of rebar with a stick clamped to the end by a dino trap, for instance) to knock the wood down.
so comparing this bit to what we see in game it's a curiosity since there is a section of path leading off and down a purposefully made path to the water. Why this is when the water is a revolving texture isn't know. Getting back to the main puzzle at hand we go to Cathy's beach.*To the shore
When the Albertosaur has left the area, Anne can feel free to explore around some more. A fairly obvious path leads further southwest, away from the house. Near the shore, it terminates at a 5m cliff, likely too tall to safely jump down, and anyway, the player would be stuck on the beach if she jumped down and survived.
so here you can see we have another objective with an unknown reason. Even the ending of the level is non existent. We go to the last heading and right into IJ. So looking at the game itself there is a mysterious ravine where the IJ river would meat up with the main stream. So after speaking with Drac I originally thought you were meant to use the pole to bridge the gap and walk across it, but after further investigating we go back to the plywood plank, a long piece. Imagining this to be a rather thin board and going by the name we came up with the impression that you were meant to bridge the gap with the board and using the boat hook as a counter balance while walking across. Hence the title "Balancing beam".Getting the hook
Once Anne makes it down to the beach, she will discover the remains of the wealthy family's picnic from the beginning of The Lost World. The tables, chairs, and other items have been strewn about by recent high winds, and some things have even become lodged in the surrounding trees, like a very long, sturdy-looking boathook. Anne must get this down by throwing stuff at it, or possibly gathering other debris around the beach like the picnic table and making a stack high enough to reach it, or at least reach it with a pole (somewhat like the construction area puzzle).