Thanks to everybody who had specific recommendations.
I was hoping for something more in New Jersey and less in New York, especially less in New York City! But... originally being a Jersey Boy I knew going into this that the Jersey Shore is not a friendly place for a deep-draft boat. The very few marinas we found who had sufficient water either had no transient slips or none available for us.
By slowly widening our search circle we did find a spot at Sandy Hook Marina in Atlantic Highlands for July. A bit further north than I was hoping for, but not too bad.
I have used ActiveCaptain as a resource and will again. I do frequently find it tedious because like everything on the internet (including what I write!) it has a some good information intermixed with errors, fantasies, and confusions. We called several places based on ActiveCaptain information and found what is written ain't necessarily so!
SM #160, Harmonie