Greetings everyone, from way out across the pond!
I´d go for a combination of wide strap, not wearing the bass too far from the upper chest (I know, very un-rockstar look, but it has helped me with a couple neck divers!) and shifting the lower bout strap pin to an intermediate point, say, where the right elbow usually meets the bass´s body when playing. It changes the angle of the instrument and helps a lot with neck diving. It usually happens most whenever the upper "horn" (where the "upper" strap pin usually is) is "below" (as in closer to the bridge) the 12th fret mark, where it should be the middle balance point of the instrument (one of my basses has a 35" scale AND short horns, and does the neck diving quite easily. On this one I had to put a very wide strap, shift the lower bout strap pin position AND relocate the upper horn strap pin to the back of the body, right where the body and neck unite a-la Gibson SG -which is another neck diver in itself!-).
