Roger -- You'll have no problem through NY harbor
if you plan it . Go back through the archives and you will find a post on how to time it.I assume the Hudson is tidal in NYC- how far upstream does it become a river? Yes it is, as the previous post said the Hudson has some tidal current up towards Albany, but I'm not sure how much. I think the Eldrdige tide book (the yellow one) should give you all the info.How fast are the currents in the Hudson? It varies. when you get towards NY Harbor it can be between 2-4 knots depending on where you are. As before get the Edlridge Tide book for hour by hour diagrams for tidail currents in NY Harbor AND Long Island Sound.How tough is it to take a C-27 under power through Hellgate?No problem at all just as long as you have a good working engine. I took my old Watkins 27 with a 15HP Yanmar up and down the East River many times. (In fact I had engine problems once and still got through fine.....Do not think you'll be able to sail through---the winds are very flukey and shifty) The secret is timing the floods and ebbing tides. If you do it correctly you will FLY through NY's East River. I had a GPS reading of almost 12 knots, just north of Hellgate, it not bad at all. The name (Hellsgate) is worse than the actually passing these days. In olden times when there where no engines and only sails, it was much tougher, plus there used to be a HUGE rock underwater right in Hells Gate. They removed it (Blew it up) over a century ago.Is it adviseable to turn into the Harlem River and go to the Hudson that way (from Long Island Sound) to circumnavigate Manhatten like the Circle Line does?No!....(I'll repeat it so it sticks) NO!...there is absolutely NO reason to go that way, there are a million low bridges on the Harlem river and they won't all just open for you. I think you might even need to notify the CG and other departments in advance.....Don't do it. It will be the biggest hassle of your life. The East River is EASY and if you time it correctly you will ricochet down the river and right back up the Hudson with the tide (I've done it). It's just timing.Plus why would you want to miss veiwing NY City on your own boat. It is a special feeling, plus you can sail past lower NY and Lady Liberty (a very special sight on your own boat....its the best!). Plus you can imagine what it might have been like to sail past the Twin Towers and pay your respects.Get the Eldridge guide....not only for NY Harbor but also timing tides on LI Sound. Its amazing how many extra miles you can make a day by timing the tides on Long island Sound. Its a 2 to 3 knot differential going against or with the tide.Good luck