Launching on the deleware for shad run

[Northjerseyoutdoorsman]

Going to fish the shad run this year but haven't launched on the delware before. Closest launch site to me is belvidere I always see lots of boats shad fishing by the bridge there and tons of boats fishing by the Easton bridge as well. How far up or down the river can you go from the belvidere launch?  And how far up or down the river can you go from the phillipsburg launch?