NYCkayaker advice on Hell Gate at max flood

[mark handy]

Hi, all --

A few of us from Inwood (northernmost Manhattan) are thinking of circumnavigating this Saturday. We are experienced paddlers but don't have a lot of practice at scheduling circumnavigations, so I'm looking for any advice on whether our plan works, particularly with regard to Hell Gate.

The proposed schedule, with tide data:

0615: leave Inwood on the Hudson's waning ebb.

0815: reach Battery Park City at the Hudson's slack.  Ten-minute rest.

0845: on the East River, whose flood started at 0630.

0930: reach Hell Gate, near max flood.

1200: arrive back at Inwood.

The main question is what to do about Roosevelt Island and Hell Gate.  We are considering two options: west channel along the Roosevelt shoreline, cross to Manhattan around 80 Street, and go west of Mill Rock; or east channel, cross to the northern tip of Roosevelt Island, look both ways, and ferry across to Mill Rock.  The issues are the security zones and the currents north of Roosevelt Island.

I have conflicting information on whether the western shore of Roosevelt Island is in the U.N. security zone. Any pointers to authoritative information?  Are there other security zones, other than bridge supports?  Maybe at Gracie Mansion?

Is it reasonable to cross the northeast-bound current north of Roosevelt Island, in order to go northwest?  My main worry here is that we will have to set such a sharp ferry angle that we will be in the channel a long time. 

All information appreciated.

Mark