Near-shore tide what to expect. "Need some Guidance" - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > Skills and Seamanship > Seamanship & Navigation
 Not a Member? 

Seamanship & Navigation Forum devoted to seamanship and navigation topics, including paper and electronic charting tools.


Like Tree1Likes
Reply
 
LinkBack Thread Tools
  #1  
Old 01-06-2014
First String
 
Join Date: Jan 2009
Location: South carolina
Posts: 828
Thanks: 43
Thanked 7 Times in 7 Posts
Rep Power: 6
ltgoshen is on a distinguished road
Near-shore tide what to expect. "Need some Guidance"

So I'm as some of you know in the process of moving to the next step in my training. I'm in the planing stages of my first over-night near shore passage. I will leave early am: 4:00 with a full moon to help and head out to the "R 4" F1 R4s @ 32-05,901"N 080-35,099W this is the channel into Port Royal sound Beaufort SC.
I intend to sail out with the tide its a 19 mile ride I figure 5.5 knots of speed? That will put me there at Day break or just after 3.45 hrs.
Then run straight east for 5nm to 32-029'899N 080-29'988 W That will take a nother 90 min,
Here, I will turn south to 32-03,997W 080-29'167W 1.92 miles = 34min
Here i will turn back west to 32-03'984W 080-34'965w this 4.92 leg take .89 min
Then I will turn North to will bring me the 4.92 nm back to to the "R 4" F1 R4s @ 32-05,901"N 080-35,099W the bell marker at the mouth of the channel. Then my hope will be to take the the Tide back in.
So here is the question." If I do this near shore how much will the tide effect my timing in the course: I plugged in the 5.5 based off motor speed.
All together time from the dock and back to the dock. 10.956 hours to cover 60.26nm
How much time will the tide cost me off shore? I know a bought the tide in and out of the river. Just need help with the offshore expectation?
Thanks again. let me know if you need more information.
Cheers, LT
Near-shore tide what to expect. "Need some Guidance"
Reply With Quote Quick reply to this message Share with Facebook
  #2  
Old 01-06-2014
RichH's Avatar
Senior Member
 
Join Date: Jul 2000
Location: Pennsylvania
Posts: 2,981
Thanks: 10
Thanked 90 Times in 82 Posts
Rep Power: 15
RichH will become famous soon enough
Re: Near-shore tide what to expect. "Need some Guidance"

Simple rule for tides when offshore: the tides go 'up' and 6 hours later (on the East Coast w/ diurnal tides) the tides go 'down'. When offshore you dont get the FLOW (current) of tides as you do in shallow estuaries / onshore .... and their 'hydraulic anomalies' due to land 'differences'. Once youre in more than 50-100 ft. deep water and well offshore, tides are 'inconsequential'.
The only place you need to be concerned with tides and their resultant generated CURRENTS is in Rivers, Bays, Inlets, etc. as in the 'ocean' the tide only go 'up' and they go 'down'.
Reply With Quote Quick reply to this message Share with Facebook
The Following User Says Thank You to RichH For This Useful Post:
ltgoshen (01-06-2014)
  #3  
Old 01-06-2014
grumpy old man
 
Join Date: Apr 2011
Posts: 3,793
Thanks: 1
Thanked 81 Times in 77 Posts
Rep Power: 4
bobperry will become famous soon enough
Re: Near-shore tide what to expect. "Need some Guidance"

Maybe try to get a Tidal Current chart book showing tide current direction and speeds at different times. We use them all the time racing in the PONW. Very useful.
__________________
Please visit my blog. It's fun to read.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Bob's Blog ....

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


Please also visit my new web site
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
  #4  
Old 01-06-2014
jimrafford's Avatar
Senior Member
 
Join Date: Jan 2011
Location: ct
Posts: 593
Thanks: 0
Thanked 13 Times in 13 Posts
Rep Power: 4
jimrafford is on a distinguished road
Re: Near-shore tide what to expect. "Need some Guidance"

Quote:
The only place you need to be concerned with tides and their resultant generated CURRENTS is in Rivers, Bays, Inlets, etc. as in the 'ocean' the tide only go 'up' and they go 'down'.

Except for thing called "The Gulf Stream"

I bought a place on Ladies Island and haven't had the chance to explore much beyond Port Royal Sound. The currents in the rivers and sound are significant. The distances you are talking about are pretty close to shore. I'm sure currents would be effected by the volume of water going in and out of the sound. Looking for some charting.
Jim
__________________
S/V Deja Vu
CS 40

Last edited by jimrafford; 01-06-2014 at 06:20 PM.
Reply With Quote Quick reply to this message Share with Facebook
  #5  
Old 01-06-2014
Senior Member
 
Join Date: Nov 2005
Location: Milton, DE
Posts: 592
Thanks: 2
Thanked 7 Times in 7 Posts
Rep Power: 10
Flybyknight is on a distinguished road
Re: Near-shore tide what to expect. "Need some Guidance"

I like the detail you are taking in your cruise planning.
The best way I know of in answering your question is to refer you to the Maritime "PILOT CHARTS" here:

https://www.google.com/search?q=pilo...ih=713&dpr=0.9
Reply With Quote Quick reply to this message Share with Facebook
The Following User Says Thank You to Flybyknight For This Useful Post:
ltgoshen (01-06-2014)
  #6  
Old 01-06-2014
Senior Member
 
Join Date: Feb 2010
Posts: 202
Thanks: 1
Thanked 3 Times in 3 Posts
Rep Power: 5
marianclaire is on a distinguished road
Re: Near-shore tide what to expect. "Need some Guidance"

Itgoshen. Have you spent time at the inlet around posted high and low tide and observed the current? The current often lags behind the posted time for high and low. If for example you plan to be back at the inlet at posted low hoping to catch the slack and then flood up river to Beaufort you will probable be way to early and will be running against the current. I have no notes on Port Royal but that is what I have seen at other east coast inlets.
FWIW. Dan S/V Marian Claire
Reply With Quote Quick reply to this message Share with Facebook
  #7  
Old 01-06-2014
Senior Member
 
Join Date: Jul 2007
Location: Philadelphia
Posts: 870
Thanks: 0
Thanked 5 Times in 5 Posts
Rep Power: 8
Ulladh is on a distinguished road
Re: Near-shore tide what to expect. "Need some Guidance"

Itgoshen
Be flexible, research the inlet tidal current and near shore currents, but be ready for the wind and near shore breeze to not cooperate. Have an alternate plan ready if needed.
__________________
1970 Havsfidra 20 by Fisksatra
On the Delaware River at Fox Grove Marina Essington PA
Reply With Quote Quick reply to this message Share with Facebook
The Following User Says Thank You to Ulladh For This Useful Post:
ltgoshen (01-06-2014)
  #8  
Old 01-06-2014
Irunbird's Avatar
Senior Member
 
Join Date: Aug 2008
Location: Charleston, SC
Posts: 293
Thanks: 6
Thanked 4 Times in 3 Posts
Rep Power: 7
Irunbird is on a distinguished road
Re: Near-shore tide what to expect. "Need some Guidance"

Something else to be aware of is that tide tables are based on algorithms (not direct observations), and are frequently off. The current will vary significantly on where you are (shallow vs deeper water) throwing another big variable in your calculations. Add to that, the surface water doesn't really start going back the other way after a tidal change for more than 1/2 an hour (in Charleston harbor, at least). Offshore, I would be willing to bet that current is downright unpredictable once you get away from a channel entrance. Sorry-- I hate to rain on your parade, but this stuff is full of all kinds of pitfalls...

Man, I hope you're not going anytime in the next few days... brrrrrr!

Last edited by Irunbird; 01-06-2014 at 09:31 PM.
Reply With Quote Quick reply to this message Share with Facebook
  #9  
Old 01-06-2014
Junior Member
 
Join Date: Jul 2013
Location: Alexandria VA
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jmallett is on a distinguished road
Re: Near-shore tide what to expect. "Need some Guidance"

Consult Eldridge's Tide and Pilot book
www dot landfallnavigation dot com/-bp002 dot html

I am not familliar with that section of the coast (mostly I sail in New England) but Eldridge covers the entire East coast.

Also learn how to add the current vector to your course vector and plot it on a chart.

From your use of Lat Long coordinates it appears that you may be planning on relying on a GPS. That's OK, but use the marine chart, course vector and current correction as well so you have a back up. Don't rely entirely on GPS, it can go wrong for many reasons.
Reply With Quote Quick reply to this message Share with Facebook
  #10  
Old 01-06-2014
jimgo's Avatar
Asleep at the wheel
 
Join Date: Sep 2011
Location: Pennsylvania
Posts: 3,012
Thanks: 71
Thanked 116 Times in 114 Posts
Rep Power: 4
jimgo is on a distinguished road
Re: Near-shore tide what to expect. "Need some Guidance"

I also see a bigger issue. Maybe I'm just dead wrong, but if you've got a good headwind on any leg, you can expect to NOT make the 5.5 kts you're using as your rule of thumb. Sure, you might get ahead of schedule on some of the legs because of the strong wind, but once you're pushing hull speed... What kind of boat, and what kind of engine do you have again? Also, since you're assuming day break is 7:30 AM, that sounds to me like you're expecting to do this some time in the next several weeks. What time will the sun set? Are you OK getting back in the dark if something happens? If you wait a month, you might have more daylight to play with as a safety factor.
__________________
- Jim
Home: Western Philly 'burbs
1980 Allmand 31
1975 Albacore 15


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Seafrost AC refrig ("shore assist") problem gstej Gear & Maintenance 3 09-19-2013 11:10 PM
"Seacock" vs. "ballcock" or "ball valve?" SEMIJim Gear & Maintenance 18 09-02-2013 06:31 PM
Washed up on shore - see the "rescue" JulieMor General Discussion (sailing related) 20 12-02-2012 09:37 PM
Shore power line "sticky" jklingenstein Gear & Maintenance 4 07-31-2012 03:45 PM
C270 Main Sail "stack Pack", Quick Cover", "lazy Bag" Install randy22556 Catalina 1 02-28-2007 12:53 PM


All times are GMT -4. The time now is 11:01 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.