Well it has no purpose to climb if you are not going to access a special area (like a operative crane house for example where you will operate crane controls, or accessing a operative winch that need to be started manually).
There is no maintenance mode in Ship Simulator where you can climb a mast to fix lights, broken antennas etc.
Since you can crash your boat in this game it would be pretty smart to also be able to fix it afterwards, like repairing damages etc
This is not a advanced feature I'm asking for but rather a simple one.
In the FPS game FarCry 2 you can fix your car if you crash it. The only thing you can fix is the engine before the car eventually explodes in front of your face