NYCkayaker Advice on Sunday Manhattan circumnavigation

[mark handy]

All:

I might do my first circumnavigation of Manhattan on Sunday, with someone who has done it once before.  I have paddled extensively from Randall's Island, around Upper Manhattan, and down to Pier 96, so I am looking for advice about the southern half of Manhattan.  Specific questions I know to ask:

When to pass the Battery and Hell Gate and any other danger points.

Is the channel on the Manhattan side of Roosevelt Island completely off-limits, or can we legally creep along the western shore of Roosevelt Island?

What other restricted zones are there?  I know only about the U.N., about the passenger ship terminal, and about keeping away from bridge piers.

If we need to be on the east side of Roosevelt Island, where should we do the crossings from Manhattan to the east channel and back to the Harlem River?

Do you experienced circumnavigators radio the ferries at each ferry terminal, or do you eyeball the situation and then make a dash for it?  Which channels do you use?

Thanks for advice on these questions and anything I've missed.

Mark