ok, first of all, did you re-equip the radar before you left dock?
at times you will go out on patrol after upgrade to another boat and you will have to complete a patrol or 2 before you will be able to equip your new boat with the radar again.
I have run into this problem with stock , and RFB 1.5.
Try a couple patrols and hope you will be able to equip it again.
