This subject comes up a lot here. " Don’t need no stinking ___________" . Making a decision about what is needed or not needed at sea is not just a matter of coming up with some scenario where it might be needed, finding a substitute for that tool or whatever.
"Same topic as Instruments, Tools (i.e. bow thrusters) and Thinking at the Margin
Here’s a post from fs:
It’s all about trade off. Evey tool, instrument, procedure or resource added to a vessel carries a cost. The question is does the benefits outweigh the costs?
An example is voyage planning. The trade off there is that the time and effort spent planning, at some point, is better used doing something else. However the principles apply to just about every decision regarding time or money.
I think its a the risk profile based on your experience.
How do I get out of this problem, possible or not possible so I need to pre plan for that
What spare parts to take etc.
Spare parts is another good example. By the law of diminishing marginal utility and the concept of opportunity costs there’s going to be a point where adding more spares is not worth it.
Not really just about hatch tents, I tried to make this point on another thread but made the mistake of putting “bow thruster” in the title.
This has come up many times. For example a person navigating needs a method to determine direction but it can be done visually. Better question is does a vessel need an additional tool (a compass for example) or method? Answer is it depends.
Other examples, additional sextant training for the crew, addition of an anemometer, adding a bow thruster, an another crew member etc.
In each case the cost / benefit has to be thought of “at the margin”.