How do I compute the best time to transit the Cape Cod Canal?

[jsc7]

The Cape Cod Canal has a challenging tidal situation and it is not clear to me how to compute the best time to make a transit. From what I understand, the biggest threat is encountering standing waves on the Buzzards Bay side, but I do not know how to compute when those would be most likely to occur.

For example, here is a set of tides for a particular day:

Cape Code Canal Current turns
WEST 4:00am
EAST 10:00am

Boston
High 5:28am
Low 11:31am

Buzzards Bay
High 3:14am
Low 10:50am

So, based on these times, if I am transiting WEST, then I would want to go sometime between 7:30am and 9:00am which means the current would be with me (GOOD) and the tide in Buzzards Bay is relatively low (GOOD). Is that the right idea?

[deblen]

Cape Cod Canal, Massachusetts Current Predictions

[mikeod]

10 ft tide on one side 3 ft on the other. Current does not coincide with high and low. You need to look up the current tables. If you have a sw wind in buzzards bay try to get there just when the current runs against you. You can anchor in onset after you get through.

[BigBoater917]

I have a lot of Canal transits but all are in a commercial vessel. Standing waves are more of an issue on the East end. All you really need to do is check the wind and see if it's against the tidal current. If there is any degree of North in your wind and forcast you should be fine for a West bound transit.

[Time2Go]

Not at home now to look but
believe Eldridge Tide and Pilot
has some diagrams of currents and
tidal flow of those parts.
I do know that there are a few spots where
ebb and flood are not in the direction
you would think
Cheers
Neil

[Bleemus]

Eldrige explains it very well.

[dfelsent]

I've been through the canal fairly often over the past decades. The eastern (Mass Bay) can have a bit of ugly with a northeast blow, but it is only for a bit.
The western end, by Onset, (which I think of as the southern end) can have the standing waves, depending on tide and weather.
First, don't be anxious. Yes, when in a 30' sailboat they can bring you to a stop. I think you have a powerboat. Just go through them slowly and you will be fine.
I try to time my canal passages, even in a 46' sailboat, to exit the canal by noon if the current will be running hard with me. If the current is anywhere near slack I don't concern myself with the time at that end.
The standing waves are a result of the normal gradient wind form the southwest plus the sea breeze from the southwest plus the narrowing of the geography funneling all that into the exit of the canal, when opposed by the full current.

Again, wind southwest against current, southwest.

Look at the forecast for the wind and the timing. The seabreeze kicks up in the afternoon. Mornings have no seabreeze.

If you are coming out of the canal and hit lousy seas, duck into Onset. The entrance is a SHARP starboard turn, but once you make that turn the current and seas vanish as if by magic. A sweet small town to stop in, with plenty of services.

Again, what I have seen in the summer just means go slow and up and down. Kind of a pain, but very manageable.

[psk125]

The trick is to time your arrival so that you have the current going with you in the direction you want to go. Anchoring at the Mass Bay end to wait can be a problem if it's a lee shore. There's a little harbor there next to the power plant, but the emphasis is on little. We haven't used it. At the Buzzards Bay end you can duck into Onset, as mentioned above, to wait for a favorable current or for the waves to diminish. We were surprised the last two times we transited the canal to be stopped by the RR bridge coming down for a train. It seems that there is now passenger rail service to the Cape from Boston, besides the once-weekly garbarge train. The sound signal for the bridge closing was not particularly loud, but there were flashing lights too. The annoying thing is that when you come up to it you theoretically always have the current pushing you into it. Make sure your engine works!

[dfelsent]

A good point above re bridges. Listen on channel 13 and 16 to avoid surprises.
The comm traffic you want to hear will be on 13. Bridges and big boats talk there.

[Steadman Uhlich]

If you are going to take your projected voyage down the East Coast of the USA, make sure you purchase and have aboard the most recent copy of the following book.

It is inexpensive and shows small charts that illustrate the currents and tides for many of the most commonly visited ports and areas from Nova Scotia to Key West.

It is easy to use, and loaded with helpful information, especially if you want to see where the currents are and what they do at times. These visual guides can be easier to understand than interpreting tables of numbers.

This book can be purchased at many marine chandleries, or ordered online. It costs about $15.

Eldridges Tide and Currents
https://amzn.to/2B4wrck

[Kolchac]

Here is my very fresh experience.
Timing:
Going to Cape Cod Bay with current (east) – looking for Flood “+”
Going to Buzzard’s Bay (west) – looking for Ebb “-“
Tide calendar 2018: Cape Cod Canal, Massachusetts Current
Current is about 5 knots, and max speed limit for boats is 10 knots. Min speed limit - do not remember – but you are ok, if you make 4 knots SOG.
Rail Bridge: I was told by officials it goes down around 3 times a day (24 h). Schedule is unknown even for bridge officials, you have to call ch13 or 16 and ask. If you are in trouble, call ch13, and they will send you help, as I told, for free.
Before the bridge, maybe 500 yards (from Buzzards’) there is a nice anchorage – Sunset marina, the channel is tricky, but OK for draft ~7’, the channel buoys do not have lights.
I was coming at nasty weather NE wind, 5-7’ (forecast for both bays) waves, from Buzzard to Cape Code bay at high flood. ~500 yards before exit I faced a bar of standing waves about 5’, depth of the bar was ~40 yards. It was bumpy, but OK. Last 400 yards was OK until exit. The canal current and coming waves created standing and breaking waves 12-15’, my 36’ sailboat was going ~30-40 degree climbing up, speed dropped from 11 to 1 knot, water was going over dodger. My worst experience in sailing life. Sailboat turned into a submarine.
Coming back in 2 weeks Cape Code bay was 7-10’ officially, but I came with slack – no problem.
Very good sailing experience, thanks to “Florence”, but I would prefer not having such.

[BigBoater917]

That's good info but I have 1 minor correction to make, the Army Corp uses Miles Per Hour rather that knots in their speed restrictions.

[NormanMartin]

Made many, many sailboat transits of Canal. If you don't have Eldridge you are making a big mistake.

When... see tables in E and go with the current. It is a fun ride and the marina in Sandwich is very nice. Call ahead.


And! Monitor both VHF Ch 16 and 13 during passage.

[BristolRI]

Hi. I'm planning to transit from West to East in 34' sailboat on August 14, 2019.
I think I understand the Army Corp tides table but appreciate anyone looking over to sequence confirm:

3:06AM - Piney Point Low Tide
3:36AM - Railroad Bridge Turns East
5:20AM - First Light
6:00AM - approx time to enter canal from Buzzards Bay
8:30AM - approx time to exit canal into Cape Cod Bay
9:09AM - Railroad Bridge High Tide
9:51AM - Sandwich Turns West (15min before Railroad Bridge?)
10:06AM - Railroad Bridge Turns West
11:28AM - Sandwich High Tide

[NormanMartin]

Too complicated. The Canal is a simple transit. Get a copy of Eldridge.

The current turns from West to East flowing on Wednesday 14 August at 3:54PM. Be abeam Cleveland Edge Light at that time and carry a fair current all the way through the Canal for the next 6 hours. The trip is just a couple hours but you will have a fair current for 6 hours beginning at about 4PM..

A couple of thoughts. First is to stage at Hadley Harbor off Woods Hole until maybe 2:30 and motor or sail to the Light, it is 6 nm and takes about an hour. Second is to stage in Wings Neck/Red Brook Harbor the day before as they have nice shore side services. Third is that sunset is 7:45 PM and there is a full moon so an overnight to anywhere is a pleasant option to have.

If you PM me I will give you my phone number and email so we can discuss in more detail.

Norm
Harwich
Averisera