My Solo, Clockwise Circumnavigation around Manhattan

by Daniele Paolo Scarpazza (scarpaz@scarpaz.com)

September 3, 2012

Abstract:

this article describes the planning and the performance of a clockwise circumnavigation around the island of Manhattan that happened on Sep. 3rd 2012 (Labor Day). The trip was originally planned conservatively, spanning 28.8NM and to be completed in 13 hours and 25 minutes, including a long break in Governor's Island to wait for slack in the Hudson's river (the average paddling speed was 2.9 knots). In the actual trip, I skipped the long break and completed the trip in 7 hours and 45 minutes, covering 27.1 NM and paddling at an average speed of 4.65 knots.

This year, unfortunately, I missed the traditional circumnavigation that Jerry Blackstone and his crew organize every year in July, for health reasons. It's not been a good year for my kayaking, in general: before today I haven't even used my kayak once. Pretty terrible. To compensate for that, I've been planning a circ for Labor Day, leaving from Pier 40 and returning to the same place.

To spice up things, I wanted my circ to be different from the usual ones I have done before. I wanted it to go around Manhattan in a clockwise direction, the opposite of what most people do. A clockwise circ is a little more complicated than a counter-clockwise one because the Hudson River keeps flooding long after the East River has started ebbing. By using the tide wheel, you can get a rough idea of the interval between the slack of the East river and the slack of the Hudson river: approximately two hours. See the timed version of the tide wheel that I made below:

More precisely, according to NOAA predictions for Sep. 3rd, the East River slacks at 18:36 (at the Brooklyn bridge) while the Hudson slacks at 20:25 (at its entrance), i.e., almost two hours later.

This complicates things because one has either to fight the Hudson's Ebb or has to find a place where to hang around for two hours. In my float plan, I thought I would stop at Governor's Island during those two hours. In my actual trip, I was early and I felt that I had enough energy to fight the Hudson's Ebb and get home much earlier than planned.

Planning:

NOAA predicts the tidal currents for a great number of stations around Manhattan, especially on the East River. These stations are characterized by name and latitude-longitude pairs, which is not exactly the most user-friendly way to select them. To ease that process, I wrote a little script that parses NOAA's web pages and represents these stations' positions on a Google Map. You can download the results below. The three versions show exactly the same data, they just use respectively a satellite, a map and a hybrid background layer, in Google parlance.

Satellite layer

Map layer

Hybrid layer

I selected a few stations that I would be interested in, and I drew a map of where they are, and at what time they slack/flood/ebb. The result is below. It's drawn by hand, but it's roughly up to scale. I used the map to plan the trip, and I brought it with me on the trip, and I ended up relying crucially on it to decide how to change my trip on the fly.

I planned the entire trip using the timings above, attempting to respect the following constraints in order of importance:

1. approach the vicinity of Hell's Gate at slack times

2. ride the Hudson's flood in the morning

3. ride the East River's ebb in the afternoon

4. avoid fighting the Hudson's late ebb in the evening.

So, I chose 8 waypoints and I planned the trip around the constraints above, with conservative estimates of how fast I can paddle (<3 knots). The results are in this table (focus on the green columns and not on the orange ones for now).

[Click the table if you are masochist and want a PDF version.]

My plan included 8 legs that connect each pair of consecutive waypoints, including a last leg back to waypoint 1 (Pier 40), and two breaks: one at the Hallets Cove (and at the Socrates Statue Park nearby), and one at Governor's Island. This second stop, almost 2 hours long, is precisely intended to wait that the Hudson River stops ebbing. The two lines in bold (waypoint 4 and 8) are expressions of the constraints discussed above. In particular, I tried to plan a pass of Mill Rock as close as possible to its slack (12:45) but I couldn't get there before 13:15 with conservative speed estimates and including the fact that I am fighting the flood in the North River as soon as I pass the Henry Hudson Bridge.

In the plan, all distances are in Nautical Miles, all the speeds in knots, all the times are in the 24-hour format, and the intervals are in hours and decimals of hour. As planned, the trip spans 13 hours and a ½, of which 10 hours spent paddling at an average speed of 2.90 knots.

Execution:

I woke up at 7 and checked the weather out of the window (cloudy, not raining, but it had rained recently, because the streets were still wet), and online (30% chance of rain). Go time.

The actual trip is characterized by higher speeds than I expected (I thank my new carbon-fiber Paddle that Randy (the owner of NY Kayak Co.) recommended me). I got to the Henry Hudson Bridge more than ½ hour earlier than planned. I stopped at the Columbia boathouse's floating deck to eat something; this stop was unplanned. The flooding currents in the North River were negligible, and I did very well in that segment, with an average speed of almost 5½ knots. Instead of passing Mill Rock on the west side (more cautions), the currents from Hell's Gate seemed safe enough to aim directly to Hallets Cove, where I got almost two hours ahead of time.

At Hallets cove I met the fellow kayakers of the Long Island City Community Boathouse, who were having an open, free kayaking event (see pictures). They were kind and hospitable, and somewhat surprised to see somebody intent in a solo circ. I stopped at the Socrates Park. (Thanks for the PortaJohns!)

I am an antsy person, and there was no way in the world that I could wait at the park till my planned departure time at 15:50. I just took a look at the tidal currents and thought that it was a good time to ride the ebb and, if really I had to wait, I could just wait longer on Governor's Island.

I got to the Brooklyn Bridge around 3PM, almost three hours ahead of my plans. It was a fast leg: for a second I saw speeds in excess of 8 knots on my GPS. Under the bridge I see on my annotated map that the Hudson's max ebbing current is only 1.2 knots. This is the decision point: either I head out to Governor's Island and I spend there a lot of time, or a turn around the Battery and I fight my way up the Hudson back till Pier 40. The second option seems way more attractive, especially because I'd be home much earlier, and I'd be done before dusk. I do that. My speed up the Hudson is around 2 knots. I try to keep closer to the walls and the piers, in an attempt to stay away from the sections of the river where the ebb is the strongest.

I finally land back at Pier 40 at 3:35. The actual trip spanned 27.1NM and lasted 7¾ hours, of which almost 6 spent paddling at an average speed of 4.65 knots, and the rest spent in the two breaks.

To give a more quantitative idea on how more problematic it is to fight the East River's ebb compared to the Hudson's, I'm posting this chart from the Steven's Institute of Technology NYHOPS forecast for 3PM.

[Click on the map for a larger version]

I wish I could post the actual GPS track, but my GPS unit's USB connector is apparently dead (saltwater corrosion?), so I had to reconstruct the times at the relevant waypoints from the pictures' timestamps.

Thanks for reading this.