Friends,

I have a Berkeley 12JC that I bought to install in a wooden boat.  The boat is a Glen-L Rampage that is designed for a jet pump but the plans provide almost nothing useful concerning pump installation.  While I'm a ways out from actually doing the install I like to plan ahead for things I'm not totally educated on.  My only real issue in understanding the install as follows:  The bottom of the boat is 1/2" thick ply with a 12" wide keel that at the centerline is 2.125" thick (plus 1/2" bottom) and has a 12 deg deadrise. 

1.  In reading the Berkeley install information, a number of options are presented for positioning the intake forward or aft depending on the angle of the transom, my transom has 0 deg angle relative to the keel which is not a choice when determining where to cut the intake hole forward of the transom?  I do not totally understand my distance from the transom forward for cutting the hole?  Having never installed one before, I need some advice.

https://www.berkeleyjet.com/Instructions/150-H02155.pdf

My choices are 9 to 16 degrees

Thank you for any help you may provide.