I'm Looking for an online reference that shows not only tidal charts for a given area but also tidal current direction and speed. Any help would be appreciated.
Tidal current online resource
- Thread starter CapnGrumpyBreeches
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Woodster, I understand that the tides go out and the tides come in. additionally I can easily find the high and low tides with charts. I am planning a 70 mile trip down the coast crossing multiple inlets and Im trying to roughly calculate my SOG with average tidal speeds, as the direction and flow of water will constantly be changing.
Barefoot Landing in Myrtle Beach has the strangest tidal change we've encountered. We grounded out by the dock before low tide and tried to find out when to expect the change. Nobody had a good idea. Less than two hours later we were floating and supposedly was just passed low tide. The distance from inlets seemed to be a key.
The wind driven tides would make current and speed calculations pretty difficult and NJ has its share. Years ago there was a post about a bridge tender in NJ the commented on the flow of water under his bridge. It eluded to the flow not changing direction during the change of tides. Some times I don't know how much I don't know. The Eldridge Tide and Pilot book carries a lot of this info for the Northeast and Chesapeake.
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The wind driven tides would make current and speed calculations pretty difficult and NJ has its share. Years ago there was a post about a bridge tender in NJ the commented on the flow of water under his bridge. It eluded to the flow not changing direction during the change of tides. Some times I don't know how much I don't know. The Eldridge Tide and Pilot book carries a lot of this info for the Northeast and Chesapeake.
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Tide tables give tabulations for the predicted times and heights of high & low tides.
Table 1 supplies this data for reference stations
Table 2 lists subordinate stations and correction factors to calculate high & low
tides for those local areas.
On the other hand, Tidal Current tables provide speed and direction of water flow
that is associated with high & low tide.
Table 1 gives detailed tabulations of the predicted times and speeds of minimum,
slack, and maximum speed of major reference stations.
Table 2 lists subordinate locations used to adjust the minimum speed data & times
for local areas.
Tidal current information can be very helpful if you are making way through narrow passes that concentrate & accelerate current flow. One can use the tables to calculate the speed of the current & direction to determine an optimal time to traverse these areas. This is especially important for sailboats with minimum horsepower to motor against strong currents.
In my locale, there are only two narrow passes that drain the entire Lake Pontchartrain & Lake Maurepas system. On days that there is a significant tidal variation, the current in these passes can definitely impede your ability to get thru. Unfortunately, I have not been able to find tidal current information for those passes; only times for high & low tide. I just have to guestimate and try to traverse the pass at slack tide or close to slack tide to avoid the times of greater current flow.
Table 1 supplies this data for reference stations
Table 2 lists subordinate stations and correction factors to calculate high & low
tides for those local areas.
On the other hand, Tidal Current tables provide speed and direction of water flow
that is associated with high & low tide.
Table 1 gives detailed tabulations of the predicted times and speeds of minimum,
slack, and maximum speed of major reference stations.
Table 2 lists subordinate locations used to adjust the minimum speed data & times
for local areas.
Tidal current information can be very helpful if you are making way through narrow passes that concentrate & accelerate current flow. One can use the tables to calculate the speed of the current & direction to determine an optimal time to traverse these areas. This is especially important for sailboats with minimum horsepower to motor against strong currents.
In my locale, there are only two narrow passes that drain the entire Lake Pontchartrain & Lake Maurepas system. On days that there is a significant tidal variation, the current in these passes can definitely impede your ability to get thru. Unfortunately, I have not been able to find tidal current information for those passes; only times for high & low tide. I just have to guestimate and try to traverse the pass at slack tide or close to slack tide to avoid the times of greater current flow.
Now I get it, if your boat speed in the water is 5 knots then 70 miles would be 14hours approximately. That takes you through the tide cycle. I tried to work this out for some DR practice but found it didn't matter because flood and ebb balanced out, there bouts.
If you're offshore about two miles along NJ, I don't think there is much effect from tides, more from ocean swell.
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Some of the stations on the site I referenced have the information you are looking for. For instance, Hell Gate NY. You really need to know what's happening before you transit that area.
http://tides.mobilegeographics.com/locations/2495.html
Well said everyone and thanks for the info!! Weather depending, I hope to be out front as much as possible where, as it was just said, I wont have to worry too much about changing currents, but being that I'm in a 22 with 5.5hp outboard, and most of our inlets in NJ (especially south NJ) aren't safe, I will have to plan for the worst which means possibly traveling the entire route on our terrible ICW. The currents in my neck of the woods are an important factor as the channels are very narrow and there is an Inlet almost every 5 miles. It just isnt practical to "wait for the tides" The coastal pilot simply says that the currents are up to 3 knots, but I know they go higher. I guess what im saying is... I need a bigger boat! haha
I found it too late to help me visualize the complex relationships between passages in the San Juans the first time we cruised up there from Olympia. I did use it last year to help us plan our trip. It requires Microsoft Silverlight to be installed on a Mac, and I remember it being a bit more user friendly the last time I used it... I could easily be wrong about that. I also thought that it was somehow tied in with apps for things like the Windows phone, so who knows what might happen to it now?
Other than this, I use the NOAA tables for specific tide and current times, and either DeepZoom or some other visualization/graphing tool to help plan how I want to time my trips through the Tacoma Narrows and other passages in the sound.
Another resource: http://earth.nullschool.net/#current/wind/isobaric/1000hPa/orthographic=-98.23,44.48,752
Click or tap "earth", and you can tailor your information to include wind, waves and currents, real-time and forecasted.
Click or tap "earth", and you can tailor your information to include wind, waves and currents, real-time and forecasted.
That would be my solution; one with an inboard diesel. Not a fan of outboards on sailboats especially when travelling. I've had way too many "pulls" at recalcitrant outboard engines, both "two" and "four" stroke. I actually injured by right shoulder once with so many hard (desperate!) pulls--that was what I called my little "20-stroke" engine! At least if it happens on a dinghy, you can row. Yes, on a sailboat you can sail IF there's room & IF there's wind!
My Navionics app has tide and tidal current info right on the map.... You hover over the indicators at various locations (the app calls them "stations")... an interactive box opens that allows you to view data... present, past and future.
https://www.youtube.com/watch?v=DLAeB8WuCt0
https://www.youtube.com/watch?v=xYtpTZwExfs
In the chart shot... the tide current station is the arrow shaped icon in the channel.
https://www.youtube.com/watch?v=DLAeB8WuCt0
https://www.youtube.com/watch?v=xYtpTZwExfs
In the chart shot... the tide current station is the arrow shaped icon in the channel.
If you're staying inside the little 5.5 will have to keep you straight as you pass any inlet. If the currents are as you say, that may be a challenge. Also at the draw bridges you have to remain stationary while the bridge raises both with and against the tide. That's a bit dicey even with an inboard. You shouldn't be alone since there are always power boats on the inside making it a bit lumpy. It might be a two day trip.
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