So I am going to build a rc square rig sailboat with firing guns, however what I want to achieve is I want a small ball bearing or someone similar to hit an opponent and cause a sensor to open a valve to let water in to allow a controlled sink.

so what I want is each time the sensor is triggered the valve/opening increases slightly more,

I am extremely new to this but I was hoping to get some information on how to achieve the sensor causing the valve to valve opening part- I would like it to be as cheap as possible and as I am unsure how to programme arduino circuits and other boards I would prefer it not to have them.
I look forward to your help and thanks in advance