As a shipbroker - One thing you will hear adnausium is the shipowner lament 'I am not a free rating service!'
What the shipowner is saying to the broker is 'stop sending me voyage business that is not FIRM and ready to fix'. Shipowners are very busy you see (surfing the net) and dont want to waste time running a voyage calculation for a client that does not have a firm cargo.
So here is a huge reason every broker should know this skill - You become the FREE rating service. Run the numbers yourself without bothering your grumpy shipowners. And here's a secret - although you will now have the skills to rate your clients business it wont be 'totally' for free...........why? Because you will get more business by adding this skill to your overall service.
Conclusion: The VS voyage estimator pack could also be called "How to find a DRY bulk freight rate without bothering shipowners!"
BTW Sorry the delay on the pack - a few hiccups - I want it to be as comprehensive as possible.