There may be too many variables for any one answer,but what is the best distance from bow to rod tip for spider rigging ? In my case,I'm in kayak.
In order to balance my kayak,( I use a Trolling motor ),and still reach my rods comfortably,I can muster 7' of rod past the bow,with 7' inside.One variable is water clarity,in my area,most would say the water stays on the murky side,with visibility no more the 2' often a bit less,perhaps 1' ( if that helps ).