For Norfolk to Boston -
Mid May is still slightly 'chancy' for an 'equinoctal gale' but not as prevalent as late March or April. Watch the development of weather systems, looking for the physical position of the Jet Stream (500 mb charts for Western Atlantic @ Ocean Prediction Center - Atlantic
) ... if the Jet Stream is far to the north and fairly straight-line then OK; if the Jet stream is 'undulating' then stay close to the inside/coast.
Ditto to where any HIGH pressure system close to the coast is located .... If close to the coast off New England, then expect NorthEasterlies ... and a 'slog' beating, so stay 'inside' or close to the coast.
If the H is off the coast and located near towards Bermuda or 'south of you', then expect SE to W-SW and smooth downwind/reaching sailing going 'north' going 'outside'.
If inside/coastal, here's some invaluable tips from a "tug driver" on passing through "hellgate" in NYC:
Use Eldrige Tide Tables to plan to cross Hell Gate at SLACK WATER.
Your best bet is to plan the trip so as to keep moving, if you're ahead of schedule run slower rather than just stopping. As a tug guy I want any pleasure craft to be predictable, I am relying on it really, which means not going in circles in confined areas. If you must stop for a bit, going east through the river I would wait well north of the battery. From there south there is just too much current as well as tug, ferry, and dinner boat traffic to be tacking or motoring around with no purpose. People do, but you asked.
Coming the other way there is plenty of room anywhere east of the Brothers, but you need to be aware of the little stuff, sand scows etc. coming off moorings, coming and going from Flushing Bay, and the other little creeks. Most traffic is passing trough.
Listen to channel 13!! Most tug guys dont really want to talk to you, but they probably will. Your best bet is to listen so you know what is happening around you. If you want to talk make your life easier by making your transmissions short, and knowing the difference between one whistle and two both meeting and overtaking. Plenty of recreational passes through everyday. Its really not a huge deal, but if you do decide to hit slack water in all likelyhood you will encounter a greater number of commercial vessels.
Another radio hint, listen to vessel traffic, the east river is channel 12, anything moving through the East River checks in at the Throgsneck or Brooklyn Bridge, and each time somebody checks in they get a rundown of all the traffic and their locations. It would be kind of like listening in on a weather net. Channel 12 is also anchorage control and the Kills south of the AK Railroad Bridge so dont get you landmarks confused.
Most of the commercial traffic especially the big stuff tries to hit slack water or within 30 minutes to an hour either side of it. Thats not to say there wont be traffic at all stages of the tide, but it is not uncommon to have multiple units on both sides of the gates stacked up waiting on each other to get through. A week ago I was fourth in line on my side coming around N. Brother Island.
You need the current tables for slack water, the tide tables wont help you here. I would agree that if your boat can manage it ride the flood through planing to be at least to Rikers Island and hour before Slack at the gate, beware of the current from pier 17 through the Williamsburgh bridge as they are very strong here and you will not want to be against them.
Going North start your trip at the Battery 2 hours after the low.
Going south start your trip from Throgs Neck 2 hours after high at the Battery.
Wear PFD's, stay in the center, have a sharp lookout for barge traffic coming around corners. Have your VHF on Ch13 and an aitr horn handy. Know what one blast means, as distinct from 2. Have a camera ready at all times for magnificant views, and 2 days after a heavy rain,a boat hook ready, if you see any bodies or other debris that may foul your passageway."