What size water pressure gauge do I need?

[83PREDICTOR]

I am looking into purchacing a water pressure gauge for my predictor because I am going to be installing a 5.5" jackplate. The question is how much dose the gauge need to read up to? 30,45,60 psi?
I have a 1993 V4 115 Johnson small gear case.

 

[illMATTic]

mke sure you get one that starts at 0 or 5 and not any higher. i think mine goes to 30. you will be pushing no more than 20 psi.