SailNet Community banner
1 - 20 of 72 Posts

·
Registered
Joined
·
5,549 Posts
Discussion Starter · #1 ·
Refer to these messages here, then please post responses in this thread.
 

·
Senior Smart Aleck
Joined
·
2,150 Posts
I am all in favor of currents when they help me get where I want to go; I am strongly opposed to currents which prevent me from going where I want to go.

The C&D canal is a surprisingly lovely area. It would be even better without the currents.
 

·
Registered
Joined
·
5,071 Posts
Several factors control the current in the C&D canal

1. Tide amplitude on the Del River is 6ft., 1.5ft. on the Ches. Bay.
2. The Del River is a 'flowing river'.... adding to the tide height by virtue of its volumetric flow direction.
3. The Filling and draining of inlets, narrow rivers and canals usually 'lags' the high/low tide times, due to hydraulic geometries such as 'choke points', bottom contours, etc. etc. etc.

... all this means your really cant look at tide data and outguess what Historically is the actual flow direction in the C&D.
This historical data of 'actual' current flow, direction and strength is found in historically compiled data based on ACTUAL observation .... such as Eldridge Tide Tables ... and some 'programs' (probably based on Eldridge).

Rule of thumb for traveling the C&D going east, and to 'ride' the 'crest' of the outgoing tide all the way down to Cape May:
Gong 'east then down' - Leave the Engineers Cove at Chesapeake City 2 hours BEFORE low tide at Chesapeake City ... maintain 6kts. and ride 'the wave' all the way down the Del. Bay

Going north on the Del Bay, 'north then west': leave Cape May Point AT low tide or shortly before dead low, maintain 6 kts. and ride the tide wave all the way up the Del. Bay and through the C&D, expect the tide to turn AT Chesapeake City and ride the ebb down the Chesapeake to at least Baltimore/Annapolis.

Note: if there has been heavy rainfall in the Delaware Valley ... all bets are off as to 'timing' due to faster and increased water flow coming 'down'. Ditto with Heavy rainfall in the Susquehanna Valley and the Susque is 'backfilling' the C&D. Ditto but opposite effect with extreme drought in those river valleys.

Other: dont travel on the Del. Bay if there is strong NW or SE winds predicted or blowing, especially if youre 'against' the tide. 6-8ft. very steep chop is 'traditional' w/ strong NW/SW 'blows' on the shallow Del. Bay.
Other2: Only two places to anchor in 'protected water' on the whole Del. Bay between C&D and Cape May: 1. Cohansey River - with BIG tide/current flow, 2. Maurice River (way off the 'beaten path')
Other3: With 'light' winds, Expect to be 'eaten alive' by 'greenheads', stable flies, various gnats, and mosquitos during 'wet' or 'spring' - the reason nobody lives along the shores of the Del. Bay.
 

·
Registered
Joined
·
1,385 Posts
There may only be a few optimal or even best times to transit the C&D either way or with respect to ebb or flood in the Delaware, point of beginning and final destination.

Even if one selects the absolute wrong time, the maximum current in opposition will be for less than 1/4 of the transit.

On the evening of June 7th the maximum current in opposition will be about 1.5 knots, an extra pint of fuel and about 2hrs extra for my transit.
 

·
Banned
Joined
·
12,359 Posts
Several factors control the current in the C&D canal

1. Tide amplitude on the Del River is 6ft., 1.5ft. on the Ches. Bay.
2. The Del River is a 'flowing river'.... adding to the tide height by virtue of its volumetric flow direction.
3. The Filling and draining of inlets, narrow rivers and canals usually 'lags' the high/low tide times, due to hydraulic geometries such as 'choke points', bottom contours, etc. etc. etc.

... all this means your really cant look at tide data and outguess what Historically is the actual flow direction in the C&D.
This historical data of 'actual' current flow, direction and strength is found in historically compiled data based on ACTUAL observation .... such as Eldridge Tide Tables ... and some 'programs' (probably based on Eldridge).

Rule of thumb for traveling the C&D going east, and to 'ride' the 'crest' of the outgoing tide all the way down to Cape May:
Gong 'east then down' - Leave the Engineers Cove at Chesapeake City 2 hours BEFORE low tide at Chesapeake City ... maintain 6kts. and ride 'the wave' all the way down the Del. Bay

Going north on the Del Bay, 'north then west': leave Cape May Point AT low tide or shortly before dead low, maintain 6 kts. and ride the tide wave all the way up the Del. Bay and through the C&D, expect the tide to turn AT Chesapeake City and ride the ebb down the Chesapeake to at least Baltimore/Annapolis.

Note: if there has been heavy rainfall in the Delaware Valley ... all bets are off as to 'timing' due to faster and increased water flow coming 'down'. Ditto with Heavy rainfall in the Susquehanna Valley and the Susque is 'backfilling' the C&D. Ditto but opposite effect with extreme drought in those river valleys.

Other: dont travel on the Del. Bay if there is strong NW or SE winds predicted or blowing, especially if youre 'against' the tide. 6-8ft. very steep chop is 'traditional' w/ strong NW/SW 'blows' on the shallow Del. Bay.
Other2: Only two places to anchor in 'protected water' on the whole Del. Bay between C&D and Cape May: 1. Cohansey River - with BIG tide/current flow, 2. Maurice River (way off the 'beaten path')
Other3: With 'light' winds, Expect to be 'eaten alive' by 'greenheads', stable flies, various gnats, and mosquitos during 'wet' or 'spring' - the reason nobody lives along the shores of the Del. Bay.
Rich,

We have success anchoring behind Reedy Island in staying out of the blows as well as chop also

Dave
 

·
Registered
Joined
·
5,071 Posts
Several factors control the current in the C&D canal

1. Tide amplitude on the Del River is 6ft., 1.5ft. on the Ches. Bay.
2. The Del River is a 'flowing river'.... adding to the tide height by virtue of its volumetric flow direction.
3. The Filling and draining of inlets, narrow rivers and canals usually 'lags' the high/low tide times, due to hydraulic geometries such as 'choke points', bottom contours, etc. etc. etc.

... all this means your really cant look at tide data and outguess what Historically is the actual flow direction in the C&D.
This historical data of 'actual' current flow, direction and strength is found in historically compiled data based on ACTUAL observation .... such as Eldridge Tide Tables ... and some 'programs' (probably based on Eldridge).

Rule of thumb for traveling the C&D going east, and to 'ride' the 'crest' of the outgoing tide all the way down to Cape May:
Gong 'east then down' - Leave the Engineers Cove at Chesapeake City 2 hours BEFORE low tide at Chesapeake City ... maintain 6kts. and ride 'the wave' all the way down the Del. Bay

Going north on the Del Bay, 'north then west': leave Cape May Point AT low tide or shortly before dead low, maintain 6 kts. and ride the tide wave all the way up the Del. Bay and through the C&D, expect the tide to turn AT Chesapeake City and ride the ebb down the Chesapeake to at least Baltimore/Annapolis.

Note: if there has been heavy rainfall in the Delaware Valley ... all bets are off as to 'timing' due to faster and increased water flow coming 'down'. Ditto with Heavy rainfall in the Susquehanna Valley and the Susque is 'backfilling' the C&D. Ditto but opposite effect with extreme drought in those river valleys.

Other: dont travel on the Del. Bay if there is strong NW or SE winds predicted or blowing, especially if youre 'against' the tide. 6-8ft. very steep chop is 'traditional' w/ strong NW/SW 'blows' on the shallow Del. Bay.
Other2: Only two places to anchor in 'protected water' on the whole Del. Bay between C&D and Cape May: 1. Cohansey River - with BIG tide/current flow, 2. Maurice River (way off the 'beaten path')
Other3: With 'light' winds, Expect to be 'eaten alive' by 'greenheads', stable flies, various gnats, and mosquitos during 'wet' or 'spring' - the reason nobody lives along the shores of the Del. Bay.
There may only be a few optimal or even best times to transit the C&D either way or with respect to ebb or flood in the Delaware, point of beginning and final destination.

Even if one selects the absolute wrong time, the maximum current in opposition will be for less than 1/4 of the transit.

On the evening of June 7th the maximum current in opposition will be about 1.5 knots, an extra pint of fuel and about 2hrs extra for my transit.
The max. eastward setting current following a max high at during the max. lunar cycle at Chesapeake City is ~2.5kts. Check out the expected current for 1/29/13 as an example. This can occur with the Delaware River 'filling', and is for 'normal' water/tide levels. Ive seen 3+kts. several times in the C&D ... all depends on how high and how low the tides are for the day.
 

·
Registered
Joined
·
5,549 Posts
Discussion Starter · #7 · (Edited)
You guys may be ovethinking all this. You are certainly making my head swim...
Certainly not the first time I've been guilty of that! ;)
Rick I thought you had Navionics or any other program since you have your computer at the helm. It tell you tide and currents and vector arrows direction at specific spots along the way or even at your location...
Yes, I use OpenCPN both at home and at the helm. It's a fantastic tool, and predicts both tide levels and currents at all the NOAA sensors just by right-clicking on the chart. However, it defaults to showing a graph for the present day. In order to bring up the tidal current graph for a day 4 months in the future, I need to click the "Next" button ~120 times. And I need to redo that every time I bring up a different graph. (Maybe a different commercial package would do this better, but OpenCPN works perfectly for almost everything else that I do.) So the old fashioned current tables, whether Eldridge or NOAA, are the best thing I have right now for future planning.

As I already mentioned, this whole thing is a learning process for me, but one that is worth it because I expect to be making a lot more transits through the canal going forward, and the lunar calendar is rather predictable so I can leverage what I learn for many future trips.

...I know how to figure out with Eldridge and all, but in todays world where I know you are comptuer savy there is an easier more efficient less time consuming way.
Any route on the Delaware that lasts less than 5 hours is pretty simple to predict - just time it to stay in the favorable current. But when you go out for more then 5 hours (downriver) or 7 hours (upriver), planning becomes more difficult because you'll encounter a tidal swing during your trip. And turning into the canal makes it even more complicated because its ebb and flood are on a different timetable than Chesapeake or Delaware. That's why you (Dave) have to stop at Reedy Point every time on your way to the ocean, and why I suggested stopping off heading from Philly to Chesapeake. As you've noted before, going the opposite direction (ocean to Baltimore or Chesapeake to Philly) can be timed to proceed without a delay at the eastern end of the canal because the currents at the canal entrance are in sync with the river currents in that direction.

That complication is the reason I cobbled together a spreadsheet planning tool for the Philly-Chesapeake. I haven't seen another tool that does this.
 

·
Senior Smart Aleck
Joined
·
2,150 Posts
My best run up the Delaware was timed to start one hour before flood at the end of the Cape May canal. Sure enough, I rode the current all the way up, through the canal, and down the Northern Chesapeake Bay. It was a wonderful experience...
 

·
Registered
Joined
·
1,385 Posts
Rich
The max current on June 12th is 2.5, but on the evening of June 7 it is 1.5

On the Delaware River our maximum flooding from up state NY is usualy in the spring and at Essington may add another 2 ft to high tide, enough to still impact the flow at the C&D. Sandy produced an extra 3ft, at Essington but did not top the seawall 3ft above high high at Delaware City, it would have been a lot worse if Sandy had tracked over the Delaware Bay or if the watershed above Trenton had a rain event.

I have been in 3 knot opposing current approach the Chesapeake City Bridge from the Chesapeake which droped my speed from 4 to1 for about 30 mins, not something I would like to repeat but it was for a finite time.
 

·
Registered
Joined
·
5,549 Posts
Discussion Starter · #10 ·
I am all in favor of currents when they help me get where I want to go; I am strongly opposed to currents which prevent me from going where I want to go...
Well the feeling's mutual - the currents oppose you almost as much as you oppose them! :laugher (Only "almost as much" because your motor power allows you to make some headway against them.)

It all depends on your frame of reference, which in the technical sense could be Eulerian or Lagrangian. (Now THAT will make your head spin! :p ) FYI, my PhD is in fluid mechanics, and I do still use some of this stuff in my day gig.
 
  • Like
Reactions: davidpm

·
Banned
Joined
·
12,359 Posts
Certainly not the first time I've been guilty of that! ;)

Yes, I use OpenCPN both at home and at the helm. It's a fantastic tool, and predicts both tide levels and currents at all the NOAA sensors just by right-clicking on the chart. However, it defaults to showing a graph for the present day. In order to bring up the tidal current graph for a day 4 months in the future, I need to click the "Next" button ~120 times. And I need to redo that every time I bring up a different graph. (Maybe a different commercial package would do this better, but OpenCPN works perfectly for almost everything else that I do.) So the old fashioned current tables, whether Eldridge or NOAA, are the best thing I have right now for future planning.

As I already mentioned, this whole thing is a learning process for me, but one that is worth it because I expect to be making a lot more transits through the canal going forward, and the lunar calendar is rather predictable so I can leverage what I learn for many future trips.

Any route on the Delaware that lasts less than 5 hours is pretty simple to predict - just time it to stay in the favorable current. But when you go out for more then 5 hours (downriver) or 7 hours (upriver), planning becomes more difficult because you'll encounter a tidal swing during your trip. And turning into the canal makes it even more complicated because its ebb and flood are on a different timetable than Chesapeake or Delaware. That's why you (Dave) have to stop at Reedy Point every time on your way to the ocean, and why I suggested stopping off heading from Philly to Chesapeake. As you've noted before, going the opposite direction (ocean to Baltimore or Chesapeake to Philly) can be timed to proceed without a delay at the eastern end of the canal because the currents at the canal entrance are in sync with the river currents in that direction.

That complication is the reason I cobbled together a spreadsheet planning tool for the Philly-Chesapeake. I haven't seen another tool that does this.
My best was last year actually. We left Cape May 1.5 hours before max Ebb at the CM Canal entrance and flew up the Delaware at 8.5 SOG, hit the tide perfect going through the canal all the way to Still Pond going 8+ again. We still had 5 hgours of dayilight so we booked for our dock in Rock Creek

As we got to the Patapsco we were chased by a waterspout comming off the land between Dundalk and Middle River. Cared the **** out of me as it was 1/2 mile behind us, but was moving east. The whole trip took 14 hours from Cape May ( Utsches) to our slip. Our best was Worton Creek before, but daylight, tides, wind a current lined up this time

Rick,

As far as fighting current, it is ineveiable if you are going to sail on the Delaware., A prime reason for moving to the Chessie:), plus think of the other achoring alternatives it will open up for you. To me a one hour ride in the car is worth fighting currents and tide changes which make you waste more than that in the big pitcure. I am waiting for the day you tell me you have decided to join us permanently:) I see it in your future as you guys move forward.

A couple hours fighting the tide wont hurt you too bad ( Colin it will because of his boat speed). I woul go into Chesapeake City before going down to Reedy and backtracking. But if you are coming from the south usually you can ride the tide up the Delaware through the Canal as james and rich have said.
 
  • Like
Reactions: jameswilson29

·
Chastened
Joined
·
4,861 Posts
Timely discussion. I'm looking to sail around DelMarVa this year, and have been wondering how to time my passage through the C&D canal.

I'm looking to make a counter-clockwise trip, so I'll be hitting the C&D from the East, motoring West. James W. has been a big help with planning.

My engine runs very well, but I'm not interested in stressing it out. I hope I don't have to run at WOT for long periods in order to time the currents.
 

·
Senior Smart Aleck
Joined
·
2,150 Posts
Even though I had 10-15 knots out of the ESE, I motorsailed the most of the way up the Delaware Bay and Delaware River to the C&D, so I could make the 8 knots over the ground necessary to ride the current for 14 hours. The difference was the boat never slowed down, so the P28 would hit 8.5 knots surfing down the front of the chop and not slow down to 5 knots on the back.

You can hear the engine running (and my rudder clicking) in the video, while I sail at maximum speed:
 

·
Registered
Joined
·
5,549 Posts
Discussion Starter · #14 ·
Even though I had 10-15 knots out of the ESE, I motorsailed the most of the way up the Delaware Bay and Delaware River to the C&D, so I could make the 8 knots over the ground necessary to ride the current for 14 hours. The difference was the boat never slowed down, so the P28 would hit 8.5 knots surfing down the front of the chop and not slow down to 5 knots on the back.

You can hear the engine running (and my rudder clicking) in the video, while I sail at maximum speed: Glorious day on the Delaware Bay... - YouTube
James,

I'm curious about the dinghy shown in your video. Is it a soft inflatable bottom, or hard bottom? How heavy is it? Have you ever had it flip on you? Do you do anything special to prevent flipping in rough seas?

My little cheapo dinghy (shown in my profile pic) was purchased on short notice just to have something on last year's Chesapeake charter. It weighs about 50 lb and stores in a bag. I have never used it - just the leak test in my living room (shown in the pic).

When I got it, it was a little better quality than I expected. It is just PVC (not Hypalon, like the better dinghies), but it is multi-ply, with a very nice nylon fabric sandwiched between the plies that prevents stretch and allows it to become very rigid when pressurized. It might actually be a viable dinghy for towing behind the boat. But I'm concerned about its light weight, and the possibility of it flipping.

Design-wise, it looks similar to your own dinghy, so I'm curious about your towing experience with it.
 

·
But if not...
Joined
·
128 Posts
Just to add to the confusion a little.

I'm working on the planning for a possible June 2013 transit to NE including the C&D/Del Bay transit. The currents shown in Garmin BlueChart mobile and on the NOAA current tables don't match up.

Here's an example

June 1, 2013 for Reedy Pt, DE

Max flood Slack Max Ebb
Garmin 03:11 06:39 11:10
NOAA 04:49 07:35 11:49

Any ideas on what might cause the differences?
 

·
Registered
Joined
·
1,385 Posts
paperbird
Look further back in this thread or the one this migrated from, TakeFive references the differences between various gauge station for the C&D.

At the Delaware end there are at least 3 stations; at the radio tower east of the route 9 bridge, on the jetty end (Reedy Point) and 1.1 miles east of the jetty end.

From Delaware bay as noted by others it is possible to time your transit with the current from bay through canal.

Going canal to bay usualy requires waiting for a favorable current down the Delaware.

Transiting from the Delaware River with the current above the canal then through the canal will require either waiting for a favorable canal current or transiting against the current for some time.
 

·
Senior Smart Aleck
Joined
·
2,150 Posts
James,

I'm curious about the dinghy shown in your video. Is it a soft inflatable bottom, or hard bottom? How heavy is it? Have you ever had it flip on you? Do you do anything special to prevent flipping in rough seas?
It is a used Achilles hypalon with a folding wooden floor insert and a wooden motor mount I don't use. I actually rowed it around St. Michaels from the museum anchorage in front of the Cabin at Perry Inn to the town dock and back to pick up ice (probably half a mile total).

It probably weighs 50 lbs without the boards in. It is a tough little dinghy.

While anchored at Kiptopeake Beach, I was awakened by the derecho passing through last summer at 12:30 a.m. Wind gusts were reported at 70-100 mph. It sounded like a freight train onshore. (This was one of the few times I thought I would die on a boat, by a tornado.) The Pearson was actually vibrating and shaking up and down, healed over at a 45 degree angle with no sails up, the wind was whistling and/or screaming through the rigging, and the Achilles was flipping over and over again. Fortunately, the anchor held and my boats and I survived fine with no damage, not even a lost oar!

I have since lashed the oars to the dinghy to prevent a loss. On my voyages, it is towed behind the boat. It tows well, but I occasionally have to haul it out of the water to empty any accumulated water from splashes/rain/waves, etc. It costs me 1/3 of a knot in speed. I tow it as a last ditch vessel in case my boat sinks. After reading about all the depictions of liferafts failing in various storms, it gives me a sense of security on my cruises, even though it is not a proper liferaft.
 

·
But if not...
Joined
·
128 Posts
Thanks Ulladh,

But those readings are for the exact same stations (by name and lat/lon) just different sources. That's what's troubling me a little. Maybe it's the source data used by Garmin?

After looking at it for a bit, I agree that going from the C to the D ideally requires riding the current through the Canal then stopping and waiting for the current to turn in the Delaware. In June, the assist (or opposition) from the current will be between 2 and 3 kts the entire 60ish mile trip to Cape May.

Of course, that all assumes the wind is either light or NOT southerly. All bets off if the wind is against the current out there.
 

·
Registered
Joined
·
5,071 Posts
Just to add to the confusion a little.

I'm working on the planning for a possible June 2013 transit to NE including the C&D/Del Bay transit. The currents shown in Garmin BlueChart mobile and on the NOAA current tables don't match up.

Here's an example

June 1, 2013 for Reedy Pt, DE

Max flood Slack Max Ebb
Garmin 03:11 06:39 11:10
NOAA 04:49 07:35 11:49

Any ideas on what might cause the differences?
Both of these are probably 'calculated' data.
Yes, my Garmin current info can lag or lead 'actual'.

Repeat, get Eldridge Tide tables -- all based on 'historical' observations.
 

·
Registered
Joined
·
1,385 Posts
Tide and currents predictions are based on historical data most of which is produced by NOAA from their various stations.

It would be interesting to compare actual conditions experienced in the canal next to one of the stations (say radio tower at route 9 bridge), with real time data from the station and predictions from the tables. Only a snap shot but it could give a tolerance range maybe plus or minus 30 min or more for the predictions.
 
1 - 20 of 72 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top